Pollsters are predicting massive defeats for the Conservatives in Kent at the general election on July 4.

Thirteen of the 18 seats in the county will go to Labour, even those in previously solid Tory heartlands.

Among MPs to lose would be Damian Green (Ashford), Damian Collins (Folkestone and Hythe), Laura Trott (Sevenoaks) and Gareth Johnson (Dartford), according to Electoral Calculus (EC).

EC analyses all polling and voting trends in the UK but does not take into account very local matters such as a controversial house-building proposal or loss of a public amenity.

But it does feed in attitudes to sensitive issues such as immigration.

The Tories currently hold 16 of the 17 existing seats in Kent but another, Weald of Kent, has been added in boundary changes.

Nationally, the latest predictions put Labour on 479 seats, the Conservatives on 92 and the Liberal Democrats on 44. The Green Party would pick up two.

The Reform UK will not get any but, with more than 11% of the popular vote, could cost the Conservatives seats in marginals.

For instance, Helen Whately’s Faversham and Mid Kent constituency would, if the EC calculations are correct, see her majority plummet from 43% (21,000) to just 2.5%. A strong Reform vote might affect her chances.

In Tunbridge Wells, the Liberal Democrats has been widely seen as the main contenders to unseat Tory Greg Clark but EC places Labour in second place.

Mr Clark’s decision to stand down may enhance the challengers’ chances.

Read more: Two more Kent MPs to stand down at next election.

Even a strong showing by the Lib Dems in the local elections on May 2, when they took control of the local council, has not shifted their position in the EC predictions.

In Folkestone and Hythe, Conservative MP Damian Collins (majority 14,500) is on course to lose the seat the Conservatives have held for decades.

Labour is predicted to have an 81% chance of winning, although local observers say that position is more nuanced.

One said: “When Michael Howard was the MP here, his majority was small at around 6,000 but it was a rock solid majority.

“He knew that but, even so, he really worked hard at being a very good constituency MP despite holding several high offices in government and in opposition.

“But the demographic has changed. A lot of people have moved out of London to live here and voting habits are a lot more fluid than they were in those days.”

The left of centre vote is strong - the Green Party now runs the local council - but could split in the general election.

However, EC founder and CEO Martin Baxter claimed tactical voting could come into play in any number of the Kent constituencies.

He added: “We have found evidence to support the idea that the centre left, particularly the Greens and Lib Dems, will vote tactically to keep the Tories out.

“Equally, there are situations where Conservatives will vote for the Lib Dems to keep the Labour Party out.”

Mr Baxter said his company is currently carrying out a study into tactical voting in the 2024 general election using “fairly large” samples.

He added: “The Tories are about 21% behind in the polls and Tony Blair was 13% ahead in 1997, so it gives you some indication of the state of things as they are at the start of the election campaign.

“Things can change, as they did for Theresa May in 2017 when she had a 20 point lead and ended up failing to win.”

A well-placed Labour source said: "Six weeks out from a general election, the idea we'd get 479 seats seems a bit ridiculous.

"It's not how it sounds out on the streets. We're doing well and we're in a much better place than we were in 2019, no doubt about that.

"But that sort of result would be beyond what has gone before. We'll have another look when we're one week out and perhaps it will be more realistic."

Analysis from Politics Editor Paul Francis

Two more Kent MPs are standing aside and won’t contest the election for different reasons. But inevitably their departure adds to a sense that the Conservatives are heading for the opposition benches if they are unable to put the brakes on a slide in support.

Anyone who saw and listened to the emotional account Craig Mackinlay, the Thanet South MP, gave about his recovery from sepsis will understand exactly why he has decided to go. Clearly, he has to put his health first and the demanding hours that MPs work would make his recovery more challenging and difficult.

He has acknowledged as much in his statement announcing his intention not to stand, saying that he has spent the last few days soul searching over whether he could continue if he was to be reelected as an MP.

As to the Tunbridge Wells MP Greg Clark, he has said it is time to pass on the baton to someone else – and the hard politics of that decision is that it will potentially help the Liberal Democratic candidate Mike Martin in his quest to oust the Conservatives from a seat which has been totemic for the Tories.

In pure numbers, there are now five MPs in the county who won’t be election candidates.

Who would have predicted that just a few days into a six-week long campaign?