LONDON (BLOOMBERG) - Mr Jeremy Corbyn, leader of the United Kingdom's opposition Labour Party, asked rival parties to support him as prime minister in a coalition to block Mr Boris Johnson's government from pursuing a no-deal Brexit.

Mr Corbyn wrote to other political parties' leaders and rebels in the Conservative Party on Wednesday (Aug 14), seeking support in a vote of no confidence in the government. He said that if that was successful, they should make him caretaker prime minister so he could delay Brexit and call a general election.

Mr Corbyn's overture was welcomed by the Scottish National Party (SNP), but rejected by the Liberal Democrats and the Welsh nationalists of Plaid Cymru.

Mr Johnson has said he is committed to delivering Brexit "do or die" on Oct 31, without an agreement if necessary - a scenario economists say would harm the economy. Members of Parliament seeking to prevent it have floated plans including replacing Mr Johnson's government with a cross-party "government of national unity" to seek a Brexit delay.

But Mr Corbyn's insistence that he should lead that administration shows the problem with this idea.

"Following a successful vote of no confidence in the government, I would then, as Leader of the Opposition, seek the confidence of the House for a strictly time-limited temporary government with the aim of calling a general election, and securing the necessary extension of Article 50 to do so," Mr Corbyn wrote.

RELUCTANT

Even Tories who are vehement opponents of Brexit would struggle with the idea of making the most socialist leader Labour has had in decades prime minister.

Mr Corbyn also got an immediate pushback from the Liberal Democrats, whose numbers grew to 14 MPs when Ms Sarah Wollaston, a former Conservative lawmaker who left the party earlier this year, joined them on Wednesday.

"Jeremy Corbyn is not the person who is going to be able to build an even temporary majority in the House of Commons for this task," Liberal Democrats leader Jo Swinson said in an e-mailed statement.

"This letter is just more red lines that are about him and his position and is not a serious attempt to find the right solution and build a consensus to stop a no-deal Brexit."

Plaid Cymru's Westminster leader Liz Saville Roberts said that while she welcomed any attempt to thwart a no-deal Brexit, Labour's leadership "cannot command the confidence of the House of Commons".

It is also possible some Labour MPs would resist - nine have left the party this year in protest at Mr Corbyn's leadership. His proposal confirms that he would not allow Labour MPs to support any other such government.

SCOTTISH BACKING

But Mr Ian Blackford, Westminster leader of the SNP - Parliament's third-biggest party - said he would be pleased to meet Mr Corbyn at the "earliest opportunity to work together".

Mr Corbyn's letter signalled that a confidence vote might not come the moment Parliament returns at the start of September. He said he would call one "at the earliest opportunity when we can be confident of success". That would mean waiting for a sign that at least one Conservative MP was willing to vote against his own government - an act from which there would be no return.

If Mr Johnson did lose a confidence vote, a 14-day period would follow in which someone else could try to form a government, or he could try to win a new confidence vote. An election would be triggered if those efforts failed.

Other plans are underway to stop the UK from leaving the European Union without an agreement. On Wednesday, former Chancellor of the Exchequer Philip Hammond warned Mr Johnson that he would work with other former ministers to try to stop a no-deal Brexit, which he called a "betrayal" of the 2016 referendum result.

Mr Johnson replied that such moves were undermining his attempts to get the EU to shift.

"There's a terrible kind of collaboration - as it were - going on between people who think they can block Brexit in Parliament and our European friends," Mr Johnson said in a Facebook Live broadcast.

As part of its no-deal Brexit preparations, the government announced it was offering a £25 million (S$42 million) contract for an express freight service to bring medicines into the country after it leaves the EU.

Mr Corbyn sent his letter to three members of the Conservative Party who have led efforts to block a no-deal Brexit - Mr Dominic Grieve, Sir Oliver Letwin and Dame Caroline Spelman - as well as to the leaders of the SNP, Liberal Democrats, Plaid Cymru and the Green Party. He did not include former Labour MPs who quit the party, whose votes he would also likely need.

The Labour leader last week asked the UK's most senior civil servant, Cabinet Secretary Mark Sedwill, for an assurance that if an election were called, Brexit would be delayed until after polling day.

Mr Corbyn on Wednesday described Mr Sedwill's response as "non-committal". Responding to the Labour proposal, a spokesman for Mr Johnson said voters now faced "a clear choice" between Mr Johnson and Mr Corbyn as prime minister.

"This government believes the people are the masters and votes should be respected," he said.

"Jeremy Corbyn believes that the people are the servants and politicians can cancel public votes they don't like."