Labour leader Jeremy Corbyn has invited senior politicians to a meeting to discuss averting a no-deal Brexit.
In a letter, Mr Corbyn said: "The country is heading into a constitutional and political storm, so it is vital that we meet urgently, before Parliament returns.
"The chaos and dislocation of Boris Johnson’s no-deal Brexit is real and threatening, as the Government’s leaked Operation Yellowhammer dossier makes crystal clear. That’s why we must do everything we can to stop it."
The meeting is scheduled to take place on August 27 at 12pm.
The letter is addressed to SNP Westminster leader Ian Blackford, Liberal Democrat leader Jo Swinson, Commons Plaid Cymru leader Liz Saville Roberts, Green Party MP Caroline Lucas, Change UK leader Anna Soubry.
Remain-backing Tory MPs Guto Bebb, Dominic Grieve, Oliver Letwin and Caroline Spelman are also copied in, as is former Conservative minister Nick Boles, who resigned the whip in opposition to the Government’s approach to Brexit.
Mr Corbyn wrote to senior opposition politicians last week and outlined proposals to call a vote of no confidence in the Government in the autumn.
Under the proposals, Mr Corbyn would lead a "time-limited" government which would extend Article 50 and call a general election.
This was met with fierce opposition from the Lib Dems, with new leader Ms Swinson saying Mr Corbyn was too divisive to lead a government of national unity.
She instead suggested senior Conservative and Labour backbenchers Ken Clarke and Harriet Harman could take the helm instead.