Steve Brine, the Tory MP for Winchester, sits down for a coffee after a morning’s campaigning in the city centre and assesses the importance of his election battle against the Lib Dems. “If I retain this seat we will be able to unblock parliament and get Brexit through,” he says. “If I don’t, then we just get deadlock part two, more delay, and we cannot move on.”

His message is that Winchester will be a key barometer of the strength of the Remain vote up and down the country on 12 December. If this seat falls to the Lib Dems, then so, too, will many others like it. For the Conservatives to win, they not only need to take Labour seats in Leave-voting parts of the Midlands and the north, but also hold off the Lib Dems in Remain strongholds like Winchester.

Brine himself is a strong Remainer who lost the Tory whip for voting for the Benn Act (to stop a no-deal Brexit) in September, but had it restored last week for backing the withdrawal bill. He resigned as a health minister in March – also over Brexit – and describes himself a “one-nation centrist”.

Brine’s moderate credentials and track record as a hardworking local MP mean he is well liked in prosperous Winchester, a seat that the Lib Dems held before 2010 but that he retained with a majority of 10,000 over them in 2017. Despite all this, it may not be enough to save him and the Tories on election day.

On the city’s streets there is not only a deep dislike of Brexit, but also a profound distrust of the prime minister, Boris Johnson, even among people who have voted Tory in the past. Kevin Hayter, who co-owns a local construction company, voted Tory in 2010 and 2015 when David Cameron was leader, but said he would never do so again because the party had changed utterly.

“They are now a tawdry, deceitful lot who kicked out all the decent one-nation Tories and I can’t vote for them. And, of course, there is Brexit. Neither will I be voting Labour. They are just pernicious and seem to spend all their time purging moderates.”

A few yards along the high street, Ian McCoy, a chartered surveyor, said the Tories had headed off to the “far right”. He believed they would be rejected by the people of Winchester. “Winchester is full of a lot of very reasonable, sensible people who don’t like that kind of politics,” he said. Asked about Johnson, he shook his head and said he was “just a buffoon”.

Certainly there are those who want Brexit delivered. Fiona Mather, a Tory member of the city council, believes that Brine will win again because “people have become more pragmatic and just want to get Brexit done”.

Facebook Twitter Pinterest Steve Brine MP. Photograph: Getty Images

But there was not a huge amount of evidence of that pro-Brexit pragmatism on a wet and wintry Friday afternoon. Most people were pragmatic in a different way: they wanted a moderate politics, a country tolerant of immigrants and close to the EU. And if that meant voting tactically to get the Tories out, then plenty were prepared to do just that.

Previous Labour voter Greig Sturges, 27, who works for children’s services at Hampshire county council, was planning to go for the Lib Dems this time. He is a Leaver turned Remainer. “In 2016 I was sucked into thinking it would be an anti-establishment vote, and I was taken in by the lies. But I would vote Remain now, definitely.”

Jo Swinson and her party, which now has 20 MPs, are sure to blitz Winchester when the campaign gets under way this week, as they will other Tory-held seats where they are strong locally, like nearby Eastleigh and St Albans. Success in this year’s European and local elections have put them on a roll.

Defections from Labour and the Conservatives have swelled their ranks in parliament and raised hopes of new conquests in areas where Remainers outnumber Leavers. Former Labour MPs Chuka Umunna and Luciana Berger are standing for the party in the Cities of Westminster and London, and Finchley and Golders Green respectively. Ex-Tory MPs Sarah Wollaston and Antoinette Sandbach will be the candidates in Totnes and Eddisbury, where they represented the Conservatives before switching; former Conservative justice minister Phillip Lee is standing in Wokingham; ex-Tory minister Sam Gyimah will be battling for them in Kensington; while former Labour MP Angela Smith will be the candidate in Altrincham and Sale West. Last week the Tory health secretary, Stephen Dorrell, was also selected as candidate in Buckingham.

Back in Winchester, Paula Ferguson, the Lib Dem candidate, who has only been a local councillor since May and describes herself as new to politics, was full of enthusiasm. She said she wanted to focus on local issues, too, to swell her vote. But as she did the rounds in the rain, few people seemed interested in the more parochial matters. A local GP, Dr Jo Batten, said Ferguson would have her vote. “Because of Brexit,” she said. “Boris Johnson is so dishonest and only sees politics as a game.”

• This article was amended on 4 November 2019. The original described Fiona Mather as one of only two Tory members of Winchester city council. There are actually 17 Conservative councillors.