A leading Tory rebel who voted down Theresa May’s Brexit deal has warned Boris Johnson that he and dozens of colleagues will block any attempt to pass the agreement again – even if the Irish backstop is removed.

Mark Francois, one of 28 Tory MPs who repeatedly held out against May’s deal, said Johnson had been very clear at a meeting of European Research Group MPs that the withdrawal agreement in its entirety was “dead”.

He told the Telegraph’s Chopper’s Brexit podcast: “He was absolutely emphatic about it, so we took him at his word. I don’t think you could revive the withdrawal agreement realistically. Even if you took the backstop out, there are too many other things that are wrong with it.”

Francois said any attempt to bring back the withdrawal bill would lead to very substantial parliamentary wrangling in the run-up to 31 October, with “weeks and weeks of people like [Dominic] Grieve and [Oliver] Letwin and co tabling wrecking amendments”.

“You’d have a running parliamentary war probably for at least a month and I don’t think that any sensible government would want that in the run up to 31 October, so in practical terms I don’t think it’s a good idea,” he said.

Johnson has said he wants to get a fresh withdrawal deal minus the backstop from the EU but he has not set out any details of how this could be expected to pass through parliament before the deadline of 31 October.

In any case, the EU is refusing to do a deal that removes the backstop, which is an insurance mechanism to maintain current customs arrangements and avoid a hard border with Ireland if no replacement has been found by the end of the transition period.

Despite maintaining that he wants a deal, Johnson increased funding for no-deal Brexit preparations by £2.1bn this week and ordered officials to look at stockpiling medicine, hiring extra border staff and launching a £138m public information campaign.

A campaign group called Stand Up 4 Brexit has the signatures of 46 Conservative MPs on a statement calling on the prime minister to “commit to leaving the EU on 31st October and abandon Theresa May’s withdrawal agreement as dead”.

The statement suggests a number of Conservatives have hardened their position against the withdrawal agreement since reluctantly voting for it in March. Some of these signatories – including Priti Patel, Jacob Rees-Mogg and Esther McVey – are now senior ministers in Johnson’s government.