Boris Johnson is set to face a showdown in Parliament later if MPs succeed in seizing control of Commons business.
No 10 officials warned the Prime Minister will call for a snap general election on 14 October if the bill passes.
Rebel Tories and Labour MPs are planning a bill to stop the UK leaving the EU on 31 October without a deal.
Mr Johnson said he did not want an election, but progress with the EU would be “impossible” if the MPs win.
Former chancellor Philip Hammond is among the Tory members who say they would vote for the bill.
The full list of ‘rebels’ willing to block a No Deal is below: