The government has “absolutely nothing to hide” from the Covid inquiry and intends to be “absolutely transparent”, a cabinet minister has said, after Rishi Sunak faced accusations of attempting to cover up the actions of senior MPs during the pandemic. The Covid inquiry, led by the retired judge Heather Hallett, has used its powers to request unredacted notebooks, diaries and WhatApp correspondence between Boris Johnson and 40 senior government figures. But the government is opposing the request on grounds that it wants to protect the privacy of ministers and officials, and is considering legal action to prevent disclosure. The Cabinet Office has been given more time to hand over the unredacted information in relation to Johnson and one of his senior aides, Henry Cook, with the material now due by 4pm on Thursday. Refusing to comply with the inquiry’s order is a potential criminal offence. Asked why the government is resisting requests from the Covid inquiry to release Johnson’s unredacted messages, the work and pensions secretary, Mel Stride, told Times Radio: “Certainly the government has absolutely nothing to hide. And in fact, over the last few months, we’ve released 55,000 different documents, I believe eight witness statements and corporate witness statements, to the inquiry. “There is this issue over the request for various WhatsApps from various individuals, which is a matter for the individuals and also for the Cabinet Office ... I wouldn’t want to be trying to sort of prejudge where all of that will land. “But other than to say that the government totally gets the importance. And that’s why we set up this inquiry, of getting to the bottom of the important lessons there are to learn from what happened because of course, many of us were deeply, deeply affected by the pandemic and the lockdown and the response to it.” In a separate interview with Sky News, Stride added: “And we absolutely intend to continue to be absolutely transparent and candid.” Two sources with knowledge of the inquiry’s requests told the Guardian the Cabinet Office was resisting handing over the material from Johnson and his aide because they feared giving in would mean all other evidence from ministers, including Sunak, would have to be submitted in an unredacted form. Sunak and Johnson were meant to have talks this week over issues such as the Covid inquiry and the former prime minister’s long-awaited peerages list but this phone call has been cancelled. Labour and the Lib Dems accused the government of a potential cover-up, while relatives of those who had died in the Covid pandemic questioned what ministers had to hide. A spokesperson for Johnson said he had “no objection” to his 24 notebooks and WhatsApps being given to the inquiry, and claimed government lawyers had already been given access to them. But the Cabinet Office released a new statement on Tuesday holding firm against giving the Covid inquiry uncensored material, with the government still considering the possibility of a legal challenge. A spokesperson said: “We are firmly of the view that the inquiry does not have the power to request unambiguously irrelevant information that is beyond the scope of this investigation. This includes the WhatsApp messages of government employees which are not about work but instead are entirely personal and relate to their private lives.” The deputy Labour leader, Angela Rayner, said: “The fact the Covid inquiry has invoked legal powers to compel the handover of crucial documents in the face of legal battles and delaying tactics shows this is a government with much to hide. “It now appears that vital evidence has gone missing. It must be found and handed over as requested if the whiff of a cover-up is to be avoided and bereaved families are to get the answers they deserve.”