The Green Party called for talks with the leaderships of Labour and the Liberal Democrats with the aim of founding a "progressive alliance" for June's general election. In London and other cities which voted to remain in the European Union, the Liberal Democrats' clear opposition to a hard Brexit could attract Labour voters who are disappointed by their party's weak stance on the EU.
And Tom Blenkinsop, who has been MP for Middlesbrough South and East Cleveland since 2010, said he would not be standing for re-election, citing "irreconcilable differences" with the party's leadership.
Rory Stewart, who represents Penrith and the Border, is hopeful that the Tories will increase their majority ahead of key Brexit negotiations.
Yet the areas Conservative MPs are confident that their party has strong appeal, and is best placed to negotiate on Brexit.
Mrs May insisted she will be out campaigning and promoting the Government's record to voters as well as her plans to "make Brexit a success and build a stronger Britain for the future". "That hasn't really worked in parliament and I'm not sure it will work in the country", she said. They'll now be the party of choice for the Brexit protest vote so watching how they do in the local election in May will be important.
"Brexit was voted for by the British people previous year".
The incumbent Prime Minister had said she did not intend to hold an election before 2020, but now says Westminster has failed to be "united".
"If you take over as Prime Minister halfway through a term, you are always vulnerable to people saying you haven't been elected".
He said: "It was in no sense about the national interest".
Adding to the pressure is May's apparent ability to bridge the class divide, with the latest YouGov poll finding she was nearly as popular with poorer voters as she was with the affluent. I think you will find the vast majority of Labour members would support these policies. Two polls over the weekend also put Labour more than 20 points behind and according to Tuesday's poll, Mr Corbyn has a negative rating of 48 per cent, in contrast to Ms May's positive rating of 33 per cent.
While unlikely to turn everything around in one go, it makes clear that a new Labour leader that is seen as a more viable alternative to the current incumbent of Number 10 would provide the boost that Labour and indeed the country so desperately needs and deserves.
No details of format or date have yet been released, but it is expected that Julie Etchingham will host the programme, as she did in 2015, when seven leaders including David Cameron, Ed Miliband and Nick Clegg took part in a two-hour showdown.