“So, it’s time for us to inject some honesty into this debate, and to identify the credible solutions that remain.
“In the coming weeks Parliament will have the chance to take control. That starts by being open about the dilemmas we face, and the credible choices that are still available.”
Earlier, Sir John Major called for a free vote for MPs to break the deadlock in Parliament over the way forward on Brexit.
The former prime minister – whose time in office was beset by divisions over Europe – said the Commons had “comprehensively” killed Mrs May’s plan.
He said there now needed to be a series of “indicative” votes to establish which, if any, the various alternative proposals could command the support of a majority of MPs.
As an “act of statesmanship”, he said all the party leaders should give their MPs a free vote to allow an “honest representation” of opinion in the House.
“It is the only way to get an absolutely honest answer from Members of Parliament and if it is a free vote it removes the danger of resignations from Government or the opposition frontbench because they disagree with their leader’s policy,” he told the BBC Radio 4 Today programme.
“It is a unique way of doing it but I think it is justified.”