May is expected to stage another vote on her deal to leave the European Union this week, but two of her ministers indicated on Sunday the Conservative government would only do so if there was the support to get it approved.

Corbyn, who has been reluctant to stage a second referendum on Britain's membership of the EU, has long said he would act to stop what he calls a "botched" Conservative Brexit.

On Sunday, he said Labour would most probably back a proposal, or an amendment, drawn up by two Labour MPs, Peter Kyle and Phil Wilson, which would seek a "confirmation ballot" if May's deal is passed by parliament.

"Yes, we will be supporting it but we've obviously got to see the wording of it," he told Sky News, adding that Labour would not support May's deal. "The priority is to make sure that we don't crash out on the 29th of March."

Corbyn has long been under pressure by members of his party to back a second referendum, or People's Vote, on Britain's membership of the EU but fears alienating those Labour voters who backed Brexit.

Meanwhile former Northern Ireland first minister Lord Trimble says "substantive changes" have been made to limit the impact of the backstop in the Brexit deal.

The peer, who has previously threatened to seek a judicial review of the Irish backstop, and historian Lord Bew said the government was now looking seriously at technological alternatives to the measure in the Brexit deal designed to prevent a hard border.

The peers also said there was an acknowledgement that there are circumstances in which the backstop could "undercut" the Good Friday Agreement rather than protect it.

Former Ulster Unionist Party leader Lord Trimble, now a Tory peer, won the Nobel Peace Prize for his role in securing the Good Friday Agreement.

MPs rejected the revised package by 149 votes last week but the peers said the changes secured with the EU had improved its chances of getting through parliament, in part because of "widespread war weariness on all sides".

In a paper for the centre-right Policy Exchange think tank they said: "Not a word of Mrs (Theresa) May's Withdrawal Agreement of November 2018, so heavily defeated twice in Parliament, has been changed.

"But we are now closer to acceptance of the same agreement.

"A widespread war weariness on all sides is a significant factor.

"But the Government has succeeded in securing substantive changes that will affect and limit the impact of the Irish backstop, if it is ever put in place at the end of the transitional period.

"The chances of the Prime Minister getting the deal through Parliament have improved."

Australian Associated Press