“I’ll vote , 100%,” said Sean, 36, a married designer and homeowner from Chester who voted Lib Dem at the last election. “The party is a lot more centrist now than it was in 2019.

“Keir Starmer may not be the most electrifying politician, but he is what we need right now. A safe, competent pair of hands who can bring some stability. And I’d absolutely trust Labour more with the NHS than the Tories. Labour will probably be more willing to invest in it.”

Sean is one of many hundreds of people from all parts of the UK who told the Guardian they would switch to a different party this UK general election, in response to an online callout asking Britons about the issues that will decide their vote, and their voting intentions.

While about a third of respondents said they had resolved to vote for Labour, again, with varying levels of enthusiasm, about another third were voters from across the political spectrum who said that they would back a different party than they had at the previous election.

The remainder said they were undecided, among them many previous Labour voters, and especially women.

Some people said they were out of frustration with manifestos they felt had little hope of achieving meaningful change.

In follow-up interviews with the Guardian, many of the respondents explained their frequently complex and personal reasoning behind their voting intention.

A key theme was that voters felt neither Labour nor the Conservatives had presented a fully credible vision for turning the country’s fortunes around, with many saying they were therefore with a focus on a string of often local and divisive issues that the two main parties have failed to centre in their campaigns. A lack of trust in politicians in Westminster who had, respondents said, , for instance about , was cited by a large number of people.

A second major theme was that hundreds of people with a diverse voting history were planning to vote tactically to topple Rishi Sunak’s government, rather than out of appetite for his challengers’ offerings.

A number of voters from Devon, as well as the wider south-west, many of them Conservative or Green supporters, said they would vote Lib Dem for the first time, hoping to edge out longstanding Tory MPs. Among them was Ian Donaldson, a 67-year-old retired teacher from Totnes.

Progressive voters in the constituency, which has been Tory for 100 years, this election.

“I’ve voted Green in 2019 but will vote Lib Dem this year,” Donaldson said, adding that the sole reason behind this decision was “the need to get rid of the Tories so the country ”.

Returning to Labour, abandoning Labour

Dozens of respondents said they were switching back to Labour after having voted for other parties in 2019, saying Starmer’s leadership had sufficiently reassured them that the party was fit for government now.

“Starmer has clearly opposed antisemitism, and that’s enough to bring me back to the Labour party, where I naturally belong,” said Michael, a retired university teacher from London who voted Lib Dem during the Corbyn years, though he added that a substantial change in Labour’s stance on the Middle East conflict could drive him back to the Lib Dems.

However, scores of people from all over the country – from areas including Reading, Gloucestershire, Devizes, south Wales, Dorset, Exeter, Oxford, Herefordshire, Suffolk, Birmingham, Nuneaton, Leicestershire, Liverpool, Manchester, Preston, Huddersfield, Morecambe, York, Barnsley, North Yorkshire, Scarborough, the Peak District and Durham – said they would desert Labour at this election, mostly for the Greens.

They felt that the party had adopted a too centrist stance on issues such as housing or the environment, had fears over NHS privatisation under Labour, or disagreed with Labour’s position on the Israel-Gaza war .

While many of these voters who were planning to vote Green or for independents came from safe Labour seats with large majorities in areas such as London, Manchester, Sheffield, Nottingham and Bristol, a number were also from battleground seats Labour will be targeting, in areas such as Workington, Northampton, Gloucester and Derbyshire.

“It’s Keir Starmer,” said Rachel Paynter, 50, a mother of two from south Wales who voted Labour in 2019, has been disabled since 2017 and is unable to work.

Her partner, who works part-time in a carpentry business, supports her and two daughters, both living at home. The family’s annual household income is about £32,000, including disability and child benefit.

“Starmer made when he wanted to be Labour leader, and then he rolled back on nearly all of them. I don’t believe he can be trusted,” Paynter said.

Her constituency, Bridgend, switched to Conservative at the last general election, gaining the seat from Labour. Her Conservative MP, Jamie Wallis, and is defending a small majority of just 1,157 that Labour will seek to demolish.

Paynter, however, has decided to support either Plaid Cymru or the Lib Dems on 4 July. “There has been little to no mention from Labour about benefits reforms, specifically Pip [personal independence payments], given that the Tory party have already ,” she said.

“Child poverty i in the UK but it looks as if Labour will not be committing to scrap . There’s also Brexit, and the green aspect [climate change].”

Constituencies with relatively higher numbers of over-50s, homeowners and people of white ethnicity are key to Labour’s hopes of winning a majority at the election, .

Nick, 69, from – one such area in middle England that Labour sees as an opportunity and where the Tories could be struggling to defend a majority of 6,758 – said he would switch from Labour to Green, because of the Labour leader’s various U-turns on policy pledges.

Like many others who said that Labour was their “political home”, Nick expressed concerns about the prospect of a Labour landslide, fearing this would embolden Starmer to turn his back on MPs and mayors pushing for more radical, progressive policy.

“I would like to see Keir Starmer not win with an overwhelming majority. I’m advising friends and family not to vote Labour,” he said.

“The feeling in Worcester is that the are without a hope, but Starmer is also showing no signs now of wanting to get to grips with a lot of the issues that are important to me, such as the welfare and care system and the climate crisis.

“Starmer says times have changed [since he made promises in these areas]. Sure, times change, but principles don’t.”

The local Greens in his area, Nick said, had put together a slick grassroots campaign focused on the most pressing concerns of local residents.

“Personal integrity and local issues, such as catastrophic flooding and sewage, matter hugely in this election, and the Greens here have got a superb team. They’re out there almost every day, always available, reporting potholes and [overflowing] litter bins, dealing with fly-tipping, helping people with accommodation.”

Tactical voting v local issues

A perceived widespread lack of enthusiasm for the two mainstream parties appeared to have motivated hundreds of respondents to vote tactically for smaller parties or independent candidates, with some seeming genuinely hopeful that even substantial majorities in their seats could be overturned, while others were concerned that divisive local issues could splinter the opposition vote.

Helen, 53, a mediator and youth group volunteer from Beaconsfield, historically a Tory stronghold with a majority of 15,000, said she was planning to vote tactically for the local Lib Dem candidate, though as a staunch Brexit remainer she had previously backed the .

Helen fears that the people of Beaconsfield will not utilise tactical voting enough to beat the Conservatives because many different local issues may split the vote.

“We and change the safe Tory seat narrative in this area. However, several tactical voting websites still say people should vote Labour here, but the Labour chap, they only brought him in last week, people don’t even know his name yet. That somebody swoops in at the last minute and just expects they’ll get in – that’s a big issue [for some people here].

“There are lots of Lib Dem boards up in Beaconsfield. This is a very wealthy area with many private schools, so is very unpopular. People worry hugely about potholes, and many don’t want any social housing built in this area. Rivers and lakes here are very polluted, and all these issues combined put this place on a knife-edge.”

Neglect of so-called safe seats

Scores of people, many of them from less advantaged households, struggling financially, or with disabilities, were feeling taken for granted by Labour and the Conservatives in supposedly safe seats, with many saying it had been the parachuting of MPs into areas they had no connection to that had been one provocation too many.

The as Labour’s candidate for the “red wall” constituency of North Durham was “an awful move”, said Andy Wiegand, a 49-year-old decorator from Chester-le-Street. He was among scores of northern voters who said they would vote Green this time, after previously voting for Jeremy Corbyn’s Labour.

“The issues that will decide my vote are social policy, including health and education, environmental issues and trustworthiness of the party leaders,” said the married homeowner and father of a 19-year-old, with a gross household income of about £40k.

“I don’t think Labour stands for anything at the moment, and nobody has knocked on my door yet, but Luke Akehurst was the final straw. He’s from Oxford, he doesn’t understand or know the area, doesn’t seem to have an interest in the north-east.”

Phil Russell, 50, a non-destructive testing (NDT) technician from Ribble Valley and, like his dad, a lifelong Labour voter, grew up in Yorkshire during the miners’ strike and said he would, for the first time ever, vote for the Lib Dems because they had made an effort to reach him.

“I’ve lived in this Conservative constituency for 20 years, and no other party has ever bothered to leaflet, it just doesn’t get touched, this Tory heartland.

“But a few weeks ago, before the election was called, a chap put a Lib Dem leaflet through the door. It turned out it was the candidate himself.

“I thought, fair play, you deserve my vote, for your effort. It’s always irritated me that the Labour party never made an effort here. I’d like to vote for Labour, but I’ll stick with my promise. Where would we be in life if we just throw away our principles, our promises?”

Barry, a 66-year-old pensioner, longstanding Tory voter and leave voter from the largely rural Conservative safe seat of Spalding in Lincolnshire, also complained about a lack of attention from other parties.

, he said, “talks a good game”, but did seem to understand “what people on the street are feeling about issues such as immigration”.

Barry’s small blacksmith business collapsed during the pandemic, forcing him into early retirement. He is worried about deteriorating properties in his area, scarce doctor’s appointments and housing.

“We’ve been here for 25 years, and we’ve never had a leaflet here from the opposition parties that would have let us know what they’re about,” he said.

“It’s a lack of choice here rather than strong beliefs that keeps people voting Conservative. If there’ll be a Reform candidate here, I’ll vote for them, though I’d be surprised if we even get one.”

Single issues overriding party loyalty

Hundreds of people, of all political leanings and from across the nation, said they were switching parties over a small number of particular and very diverse issues, such as sewage in rivers, Palestine, private school fees and Ulez schemes.

One such “single issue” voter from South Cambridgeshire, who wanted to stay anonymous, said he had voted Lib Dem in 2019 but would tick the Conservative box on his ballot this time over an issue he described as “Labour’s and the Lib Dem’s war on private vehicles”.

A number of people said they would ditch Labour because of Gaza, among them Ellen, 23, a university student from London. She said she had voted for Labour in 2019 and was now planning to vote Green because of “Keir Starmer’s stance on Israel/Palestine. Will he stop arming Israel?”

A 45-year-old nurse from South Gloucestershire, who voted Labour in 2019, pledged to vote Tory this summer over a single issue: “My Labour-led council is planning to build about 14,000 homes in the next 20 years in a 10-mile radius around us. I’ll do whatever necessary to stop the destruction of our green spaces and unfortunately until these plans stop, it’ll mean voting for the candidate who is most likely to beat Labour.”

“Honesty and integrity”

Many dozens of voters cited dishonesty and a lack of morality among politicians as a major factor shaping their vote, particularly those from the north of England, many of them in red wall seats.

Labour and the Conservatives were both lambasted by voters for having betrayed their trust.

Susan, 73, was one of a number of people from Milton Keynes, another battleground area, who said they would switch to Labour. “I have always voted Conservative. I’ll be voting Labour in July,” she said.

“Boris Johnson lied continuously during his time in office. Then we had Truss. What a disaster. Now Rishi, who hasn’t a clue.

“[The Tories] have made life so difficult for our children. House prices, mortgages and energy prices are sky high. All the red tape following Brexit. NHS waiting lists are so long.”

Ken, from Durham, a retired Labour voter who said he would now likely vote Green, said the second most important factor in his decision, after “Brexit, the elephant in the room”, was “honesty and integrity”, which he felt were currently “missing from politics”. “It now seems OK to lie and not face any consequences,” he said.

Mike, 26, a leave voter from Poole who has been working in IT since leaving the army, agreed that honesty was a huge factor in this election. He was also among many who lamented “broken promises” made by pro-Brexit politicians and was one of various voters who said they had primarily lent the Conservatives their vote to keep Corbyn out of No 10.

“When I voted Tory in 2019 I didn’t like Corbyn, and Boris Johnson said many of the right things about levelling up and more money for the NHS. He just didn’t do any of them. This time, I’ll tactically vote Lib Dem to get the Tories out,” Mike said.

“ – that’s when the Tories lost me probably, and it’s definitely damaged my trust in Conservative politicians.”

He said housing was now the biggest policy issue for him, after he had to spend weeks in a hotel recently when he was finding it “almost impossible” to find a place to rent in Dorset.

Dave, 54, from Lancashire, who said he was “not strongly against Brexit”, said he had carefully read different manifestos and that he would vote Green in the constituency of Preston after voting for Labour in 2019.

He said: “I think this is the kind of election where I think voters have to actually stand up for what they really believe in.”