Published: 6:00 PM December 10, 2019 Updated: 6:11 PM September 17, 2020

Third-placed Liberal Democrat and Labour candidates in 20 seats are being asked to halt campaigning in favour of the Remain-supporting candidate with the best chance of helping to prevent a Boris Johnson landslide.

The last minute calls come from campaign group Vote for a Final Say as a new poll suggests a small group of Lib Dem voters are set to hand victory to a hard Brexit Conservative in the ultra-marginal seat of Stockton South.

The Survation survey shows the constituency's anti-Brexit Labour candidate Dr Paul Williams, who held the seat for the past two years, is polling just three per cent behind the Conservatives.

However, if he received the endorsement of the Lib Dem candidate, Dr Williams could be re-elected by a margin of 48 to 43 per cent, says Vote for a Final Say.

Stockton South is not the only marginal seat in which they would like a third-place candidate to step aside

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Vote for a Final Say has published a list - shown below - of 20 candidates from Labour or the Lib Dems who they say risk guaranteeing the Conservatives a parliamentary majority.

The campaign, which has used recent MRP data to draw up its list, will encourage supporters to contact these candidates through social media asking them to cease campaigning and to back the Remain rival with a better chance of beating the Tories.

The plea comes after the three largest pro-EU campaigns issued a joint statement announcing that they have come to largely the same conclusions on tactical voting recommendations across marginal seats.

Remain campaigns agree on tactical voting recommendations for almost every marginal seatDr Williams told Vote for a Final Say: "If Brendan Devlin asked people to vote for me instead of the Liberal Democrats here in Stockton South then it would not only be a kind and typically principled act, but it would also stop us going back to having a Tory MP.

"I've always been sensible and pragmatic and have worked closely with other parties - I am proud to have been endorsed by the Stockton Green Party and by Thornaby's independent Mayor Steve Walmsley.

"If I were re-elected I would fight for a fairer voting system that makes every vote count, so that this type of compromise would never have to happen again."

Labour's third-placed candidates in seats like Cheltenham and Cheadle will face similar pressure in the closing hours of this campaign.

Peter Kyle, the Labour MP for Hove since 2015 and a leading supporter of a final say referendum, said: "This election is like no other so we're all having to think differently to stop Boris Johnson's brutal Brexit.

"If you believe in your heart that Labour can't win in your area but an anti-Brexit party can, then just this once put your Labour values into action in a different way by lending your vote to a 'stop Boris Johnson' candidate. Our country cannot take another five years of Tory government, let's do whatever it takes to stop it happening."

Many activists are voting with their feet by working in neighbouring constituencies where their party stands a better chance.

Mark Perryman, a Labour tactical campaigning organiser, said: "If we want to stop Johnson's Tories getting a majority then we have to defeat Conservative candidates.

"Where I live, Lewes, there's currently only one party that can do that, and we all know which one it is. The choice here, for Labour and Green voters, even if it's not our first choice, is that simple.

"Meanwhile for the past six weeks carload after carload of us have been going to Hastings, Crawley, East Worthing, Labour's Sussex target seats. Some of us will vote tactically in Lewes, some not but what we all want is Labour to win where it can win."

Rob Castell, the former Lib Dem candidate in Beaconsfield who stood down in favour of rebel former Conservative Dominic Grieve, said: "Third placed candidates risk muddying the waters on this choice. I understand candidates will be reluctant to stand back from campaigning, but with some seats being decided by a handful of votes, it's more important than ever that the choice is clear for voters."

Tim Walker, who stood down as the Lib Dem candidate in Canterbury to give Labour's Rosie Duffield a better chance, said: "People will remember us for what we do. Will they say we were true to ourselves? Did we do what's right? I got into politics to try to make things better. Not to make them worse.

MORE: Tim Walker explains why he stepped down as Canterbury Lib Dem candidate

"I could not win in Canterbury, but by putting my future with my party first - ensuring I'd personally be rewarded for doing this bit of dirty work for them - I'd have guaranteed a Tory Brextremist a seat in the House. I'd also have deprived the principled and independent-minded Rosie Duffield of hers. I decided I wanted no part in that.

"I beg other Lib Dem and Labour candidates in identical situations to my own to now look to their consciences and abandon their disreputable campaigns.

"I know of dozens who know deep down what they're doing is wrong. If Johnson's to be stopped from getting his mandate for a hard Brexit, they should do something else, too.

"They should announce they are voting for the Labour or Lib Dem candidate who can win - and urge their supporters to do likewise I beg them to be their own men and their own women at this time of reckoning. To face up to reality, before it is too late."

The full list of third-place candidates being asked to stand down is below

Each candidate's polling percentage is greater than the Tory lead in that seat.

Canterbury - Claire Malcomson (Lib Dem) - polling at 9%

Cheadle - Zahid Chauhan (Labour) - polling at 17%#

Cheltenham - George Penny (Labour) - polling at 11% Wakefield - Jamie Needle (Lib Dem) - polling at 6%

Warrington South - Ryan Bate (Lib Dem) - polling at 9%

Winchester - George Baker (Labour) - polling at 10%

Weaver Vale - Daniela Parker (Lib Dem) - polling at 8%

South Cambridgeshire - Dan Greef (Lab) - polling at 26%

Chingford & Woodford Green - Geoff Seef (Lib Dem) - polling at 13%

Sedgefield - Dawn Welsh (Lib Dem) - polling at 6%

Gower - Sam Bennett (Lib Dem) - polling at 6%

Stockton South - Brendan Devlin (Lib Dem) - polling at 8%

Putney - Sue Wixley (Lib Dem) - polling at 27%

Eltham - Charley Hasted (Lib Dem) - polling at 14%

Bristol North West - Chris Coleman (Lib Dem) - polling at 9%

Croydon Central - Simon Sprague (Lib Dem) - polling at 10%

Enfield, Southgate - Rob Wilson - (Lib Dem) - polling at 11%

Wirral West - Andy Corkhill (Lib Dem) - polling at 9%

Warwick and Leamington - Louis Adam (Lib Dem) - polling at 11%

St Albans - Rebecca Lury (Labour) - polling at 19%