THE Tories will lose a snap general election because they are woefully underprepared to fight one, party chiefs have concluded.

Senior Conservative officials have privately warned Theresa May that she could face disaster if she calls a new nationwide poll to try to unblock the Brexit logjam.

PM Theresa May is being privately warned against calling a snap General Election as the Tories could face disaster Credit: AFP

Secret party projections instead put Jeremy Corbyn in No10, at the helm of a rainbow coalition government including the SNP and the Lib Dems.

In another blow for the PM’s prospects, new research carried out by a senior former No10 adviser to Mrs May has revealed dozens of sitting Tory MPs are facing ultra tight marginal races.

The alarm-bell internal Conservative Party assessment - whose findings have been shared with The Sun - reveals:

The Tories’ data base of voters nationwide is badly out of date and now far behind Labour’s, having seen little update since 2015.

The party’s grass roots membership is badly demoralised, after many months of infighting with CCHQ over money and structural reforms.

The Tories currently don’t even have an opinion polling firm under contract – seen as all-important to fight any election - with a tender currently out to hire a new one.

With its massive new army of close to 500,000 members, Labour are now seen to severely outgun the Tories and have deployed them to compile a substantial database of voters to target in any ‘ground war’.

The bombshell comes after some Tory MPs have begun to call for a snap election to solve the Brexit deadlock in Parliament, preferring it to a second referendum.

But The Sun can also today reveal analysis by centre-right think tank Onward that will further terrify Tory MPs.

MARGINAL SEATS AND THE BREXIT FACTOR

Of the 317 seats that the Tories won in 2017, 40 are held by a margin of 5% or smaller - and Labour hold second place in 35 of them.

There are 20 Conservative-held seats with an even tighter margin of less than 2.5%, of which 17 have Labour in second place.

And nine Tory MPs won last year with a hair’s-breadth majority smaller than 1%.

Mr Corbyn needs to win just 30 more seats to become the largest party in a hung Parliament.

Party strategists also expect him to make big gains in Scotland, where 46 out of its 59 seats are vulnerable to a 5% swing to Labour.

One opinion poll this month gave the Tories a 6 point lead despite the party’s Brexit civil war.

But others have given Labour a lead, and trackers put the two parties neck at neck with Mr Corbyn’s party on 38.4% and Mrs May’s 38.1%.

Onward’s Director Will Tanner, who advised Mrs May for four years until 2017, said: “The prospect of a General Election should concern anyone who fears the damage Jeremy Corbyn would wreak on Britain’s economy and security in Downing Street.

“It would take a tiny swing for Labour to sweep dozens of seats to become the largest party - with 40 Conservative constituencies held with a majority of just 5 per cent or smaller.”

Mr Tanner added: “If Conservatives can get back to a reforming domestic agenda, there is no reason they can’t win over wavering voters in key marginals and regain a working majority - but an election now, with Labour at the gates, risks it all”.

One senior minister also told The Sun on Tuesday that the Tory vote has collapsed in middle class pro-Remain areas.

The minister said: “I walk down smarter streets in my constituency these days that were once strongholds and don’t want anything to do with us now.

“If you knock on a door and they have books on their shelves, you can be pretty sure these days they’re not voting Tory.”

It emerged that the party’s chief executive Sir Mick Davis is trying to put in on a war footing.

During a briefing at its HQ, Mr Davis was reported to have said the party needed to ensure it had the “resources in place” for a snap election.

Jeremy Corbyn will get the keys to No10 if Theresa May calls a snap General Election to unblock Brexit, Tory chiefs warn Credit: AFP or licensors

Labour could form a rainbow coalition with the Lib Dems, pictured their leader Vince Cable at Westminster Credit: Getty Images - Getty

The SNP could also prop up a Jeremy Corbyn Government, pictured their Westminster leader Ian Blackford Credit: PA:Press Association/PA Images

GOT a news story? RING us on 0207 782 4104 or WHATSAPP on 07423720250 or EMAIL exclusive@the-sun.co.uk