Gordon Brown: consequences of a no-deal Brexit must be independently assessed
Mr Brown said MPs should seize control of the House of Commons agenda to ensure the full impact of leaving the EU without an agreement is made clear.
Referring to MPs, Mr Brown told BBC Radio 4's Today programme: "I think what they should do is agree that they take over the business of the House of Commons for a day, as they did before, pass a law that says that the Government must instruct and produce an independent report on the consequences of a no-deal.
"And that should be before the House of Commons before we ever go ahead. That would be a sensible way forward."
Prime Minister Boris Johnson has insisted Britain will quit the EU by October 31 with or without a deal with Brussels, and has said that the prospect of leaving with no-deal was now "touch and go".
Tomorrow, Labour leader Jeremy Corbyn will meet with other opposition party Westminster leaders to prevent a no-deal Brexit, with Liberal Democrat leader Jo Swinson keen to examine how to seize control of Commons business, oust Boris Johnson and install an emergency government of national unity.
Ms Swinson has also called for Mr Corbyn to clarify his own stance on whether he wanted to reverse Brexit, and she suggested that any interim government which took office following a vote of no confidence in Mr Johnson should be led by a figure who could command support across the Commons - something she said Mr Corbyn would not be able to do.
She said: "The meeting between opposition leaders is an opportunity to reassure the British public that politicians are leaving no option off the table when faced with crashing out of the EU.
"We cannot allow party politics to stand in the way of finding a solution that works to prevent the national crisis approaching us.
"The Liberal Democrats stand ready to do everything we can to prevent not only a no- deal Brexit, but to stop Brexit altogether."
In her letter to Mr Corbyn, the Lib Dem leader said an emergency government formed after a successful no confidence vote "must have the majority support required to request and secure an Article 50 extension" to delay Brexit beyond October 31.
But many MPs opposed to a no-deal Brexit, in particular "key Conservative MPs", have rejected Mr Corbyn as the leader of a caretaker government.
She warned the Labour leader: "Insisting you to lead that emergency government will therefore jeopardise the chances of a no confidence vote gaining enough support to pass in the first place."
Ms Swinson said veteran MPs Tory Ken Clarke and Labour's Harriet Harman had indicated they would be willing to lead an emergency government.
She also called on Mr Corbyn to spell out whether he was opposed to Brexit altogether.
"You have previously said that you would seek to negotiate a Labour Brexit if in power, and Labour's shadow chancellor John McDonnell recently suggested that Labour could remain neutral in a future People's Vote," she said.
"It would be appreciated by Remain voters across the country that both your personal and your party's position could be clarified in these discussions."
However Gordon Brown, who is expected to make further intervention in the Brexit debate when he speaks at Edinburgh's Book Festival this afternoon, has criticised Ms Swinson and others for "wasting time" filling cabinet posts in a government "that doesn't exist" and urged opposition MPs to speak directly to the EU to have the October 31 Brexit deadline extended.
Writing in a Sunday newspaper Mr Brown said: "Of course some still believe we should keep up the threat of a no deal to get Europe to the negotiating table but even the Europeans we are bargaining with can see that putting a gun to your own head – and saying you’ll shoot yourself if you don’t get your own way – is a self-defeating tactic.
“It is time for MPs to listen to the rising opposition of British people – and do everything in their power to stop us crashing out on October 31.
“Instead of the silly season madness of self indulgently nominating each other to a so-called ‘national unity government’, Britain’s opposition parties should this week be talking to European leaders, and calling on them to drop the October 31 deadline.”