Jeremy Corbyn has warned his successor as Labour leader not to get into a government of national unity with Conservatives to help fight the coronavirus.

The outgoing leader, who is expected to be replaced by Sir Keir Starmer on Saturday, said that giving up the responsibility to oppose and challenge the government would be “a negation of what our democratic society is about”.

His comments came as former Conservative leader William Hague said it would be “constitutionally correct” for prime minister Boris Johnson to brief the new Labour leader directly on the government’s strategy, suggesting that this would help relieve pressure on ministers from the opposition.

“Really the leader of the opposition is owed explanations from the government about what they’re doing,” Lord Hague told The Times.

“You probably want the leader of the opposition to have a good understanding of what the bottlenecks are and what the difficulties are. Otherwise he’s going to be putting you under pressure to do things that you can’t do. So it’s in the government’s interest as well as in democracy’s interest for that sort of meeting and discussion to take place.”

But asked whether Labour should be offering its support to the government to help the country get through the coronavirus crisis, Mr Corbyn told the Daily Telegraph’s Chopper’s Politics podcast: “It’s the duty of opposition parties to hold it up into account and that is exactly what we’re doing.”

Mr Corbyn has said that Labour would have moved faster to ramp up Covid-19 testing if he had been in power.

“I think we should be challenging the government and challenging them on the economic response, challenging them on job security, and that is the way to get better government and better decisions,” he said.

“If everybody got together and said ‘we’re all absolutely in this together; we won’t criticise each other’ – that is a negation of what our democratic society is about.”

But leadership contender Lisa Nandy repeated her call for a “national Cobra” emergency committee, in which government ministers would be joined by representatives of opposition parties and devolved governments, and said that Labour should be offering ideas on how to defeat the virus.

Asked if Downing Street should be offering direct briefings to Labour, Ms Nandy told BBC Radio 4’s Today: “I think that’s absolutely right. I actually think we should formalise that arrangement, and that the government should set up a national Cobra, which involves the opposition, as well as leaders in Scotland and Wales who have also been invited to attend on an ad hoc basis.

“We need to work together to get the country through this crisis. We need to understand the strategy so that we can give the public confidence.

“But we also need to be able to input into that strategy. We saw it with issues early on like sick pay, which Matt Hancock said hadn’t been thought about initially but were obviously really, really important if we’re going to be able to give people the ability to follow the guidance.”

The battle to replace Jeremy Corbyn as Labour leader Show all 8 1 /8 The battle to replace Jeremy Corbyn as Labour leader The battle to replace Jeremy Corbyn as Labour leader Keir Starmer The former director of public prosecutions undoubtedly has announced that he is standing for the leadership. He is highly-regarded by both left-wingers and centrists in the party. As Labour’s shadow Brexit secretary, he played a key role in the party’s eventual backing of a second referendum. Before becoming an MP, he was a human rights lawyer - conducting cases in international courts including the European Court of Human Rights. Launching his bid, Starmer said that Labour must listen to the public on how to change "restore trust in our party as a force for good." A YouGov poll places him comfortably in the lead as the preferred candidate of 36% of party members EPA The battle to replace Jeremy Corbyn as Labour leader Lisa Nandy Wigan MP Lisa Nandy has announced she wil stand for the leadership. In a letter to the Wigan Post she said she wanted to bring Labour "home" to voters in its traditional strongholds who have abandoned the party. Nandy went on to say that she understands "that we have one chance to win back the trust of people in Wigan, Workington and Wrexham." A YouGov poll shows that Nandy is the first preference for 6% of partymembers. Getty The battle to replace Jeremy Corbyn as Labour leader Rebecca Long Bailey A key ally of the current left-wing leadership of the party, the Salford & Eccles MP is viewed in some quarters as the natural successor to Mr Corbyn and describes herself as a “proud socialist”. Highly regarded by the shadow chancellor, John McDonnell. She won also won plaudits for her performance filling in for Corbyn both at prime minister’s questions and during the general election debates. The shadow business secretary grew up by Old Trafford football ground and began her working life serving at the counter of a pawn shop. Launching her leadership bid, Long Bailey said the party needs to make the positive case for immigration as a "positive force." She also broke with Corbyn over Trident, saying "If you have a deterrent you have to be prepared to use it." PA The battle to replace Jeremy Corbyn as Labour leader Angela Rayner - Deputy leadership Shadow education secretary Angela Rayner has joined the contest for deputy leadership of the party. After ruling herself out of running for the leadership, the Ashton-under-Lynne MP launched her bid for deputy warning that Labour faces the "biggest challenge" in its history and must "win or die." She is close with leadership contender Rebecca Long Bailey PA The battle to replace Jeremy Corbyn as Labour leader Rosena Allin-Khan - Deputy leadership Shadow sport minister Rosena Allin-Khan said Labour need to listen with "humility" to lost voters as she launched her bid for the deputy leadership. Writing in The Independent, the MP for Tooting refelcted: "We shouldn’t have ignored the warning signs in Scotland, and now we’ve paid the price in northern England, across the midlands and in Wales." PA The battle to replace Jeremy Corbyn as Labour leader Dawn Butler - Deputy leadership Shadow women and equalities secretary Dawn Butler was first to announce her bid for the deputy leadership. The Brent Central MP has served in Jeremy Corbyn's shadow cabinet since 2016 PA The battle to replace Jeremy Corbyn as Labour leader Ian Murray - Deputy leadership Labour's only MP in Scotland said that the architects of the party's "catastrophic failure" in the December election can not be allowed to lead the party forward PA The battle to replace Jeremy Corbyn as Labour leader Richard Burgon - Deputy leadership Shadow justice secretary Richard Burgon is standing as a continuity candidate, flaunting his loyalty to Jeremy Corbyn and saying it is wrong to blame the current leader for the election defeat PA

As Corbyn prepared to step down after five years at the helm, his wife Laura Alvarez broke her longstanding silence to voice her pride in her husband and declare she would “never regret our dream of a better quality of life for everybody”.

Writing in the Daily Mirror, Ms Alvarez took aim at Mr Corbyn’s opponents inside the Labour Party and urged his supporters to keep up their fight for the values he represents.

“It has been hard for me to watch my husband vilified and hear his words twisted by his political opponents,” she said. “It has been harder to watch him attacked by his party.

“I want to thank those who voted for Labour, and especially those who stood with my husband.

“We know you shared our values. If equality, humanity, honesty and kindness are called Corbynism, then that’s all right with me.”

Jeremy Corbyn and wife Laura Alvarez cast their votes in the 2019 election (PA)

With Sir Keir thought likely to sideline the hard left if he defeats “continuity Corbyn” candidate Rebecca Long-Bailey as expected on Saturday, Ms Alvarez sent a defiant message to her husband’s supporters not to abandon his cause.

“I will never regret our dream of a better quality of life for everybody,” she said.

“It is now up to our movement to ensure it does not remain a dream.”

Mr Corbyn himself indicated he may resume his role as a backbench rebel under the new leadership, saying: “It depends what the votes are and what the issues are – I always believe in being true to oneself.”