The UK government has asked the Queen to suspend parliament just days after MPs return to work in September - and only a few weeks before the Brexit deadline.
Boris Johnson said a Queen's speech would take place after the suspension, on 14 October, to outline his "very exciting agenda".
But it means MPs are unlikely to have time to pass laws to stop a no-deal Brexit on 31 October.
Tory backbencher Dominic Grieve called the move "an outrageous act".
He warned it could lead to a vote of no confidence in Mr Johnson, adding: "This government will come down."
But the prime minister said it was "completely untrue" to suggest the suspension was motivated by a desire to force through no deal.
He said he did not want to wait until after Brexit "before getting on with our plans to take this country forward", and insisted there would still be "ample time" for MPs to debate the UK's departure.
"We need new legislation. We've got to be bringing forward new and important bills and that's why we are going to have a Queen's speech," he added. (BBC)