Around 160 MPs have signed a document dubbed the Church House Declaration in opposition to a no-deal Brexit.
The text said: “Shutting down Parliament would be an undemocratic outrage at such a crucial moment for our country, and a historic constitutional crisis.
“Any attempt to prevent Parliament sitting, to force through a no-deal Brexit, will be met by strong and widespread democratic resistance.”
Those who have signed the declaration pledged to do “whatever is necessary to ensure that the people's voice is able to be heard".
Jeremy Corbyn met with opposition leaders earlier in the day, and has promised to put forward a motion of no-confidence in Boris Johnson “at a time of our choosing”.
He said it will not be the first item brought forward when Parliament returns on September 3.
He has also written to 116 Conservative or independent MPs who voted against no deal, including Theresa May and Philip Hammond, to ask for their support.
SNP Westminster leader Ian Blackford said the party will “do everything we can to stop Brexit” and the numbers are “stacking up against” Mr Johnson.
“Parliament must grasp this opportunity, unite to stop Boris Johnson shutting down democracy - and be ready to use all mechanisms to block a no deal disaster, including deploying legislation as a priority,” he said.
Jo Swinson was among those who signed the declaration
Liberal Democrat leader Jo Swinson said she took part in a “very positive meeting” with other opposition party leaders, however they did not discuss who would lead a caretaker government should the no-confidence vote prove successful.
Ms Swinson has previously said Mr Corbyn could not command enough parliamentary support to serve as interim Prime Minister.
Mr Corbyn said the “priority is to ensure we don’t crash out of the EU” and “it's nothing to do with whether people like me or not.”