Rishi Sunak’s government has been accused of a cover-up after telling the Covid inquiry it did not have Boris Johnson’s pandemic notebooks and WhatsApp messages, even though government lawyers were given the material. The Cabinet Office has been refusing to hand over unredacted versions of Johnson’s correspondence and documentation, and is now claiming to the inquiry that it does not have the WhatsApps or 24 notebooks in its possession. However, allies of the former prime minister said he had given access to the material to government-appointed lawyers paid for by the Cabinet Office. A spokesperson for Johnson said the Cabinet Office had not requested it directly, adding: “Mr Johnson has no objection to disclosing material to the inquiry. He has done so and will continue to do so. The decision to challenge the inquiry’s position on redactions is for the Cabinet Office.” The government-appointed lawyers are believed to have reviewed the unredacted material before determining it was “unambiguously irrelevant” to the investigation. With the standoff continuing, the Cabinet Office is still considering legal action to prevent unredacted material being handed over to the official inquiry, chaired by Heather Hallett, a retired judge and crossbench peer. Labour said the situation had the “whiff of a cover-up” while the Lib Dems said this “dog ate my homework-type excuse from the government simply doesn’t stand up to scrutiny”. Susie Flintham, a spokesperson for the Covid-19 Bereaved Families for Justice campaign group, also questioned why the Cabinet Office was trying so hard to stop the information being released. “The lengths that the Cabinet Office are going to in order to stop Boris Johnson’s WhatsApp messages and diaries from being shared with the Covid inquiry should alarm everyone,” she said. “This inquiry needs to get to the facts if it is to learn lessons to help save lives in the next pandemic. So why are the Cabinet Office standing in their way? Our members are wondering what they are hiding?” Bob Kerslake, a former head of the civil service, told the BBC there was “some cover-up going on here to save embarrassment of ministers”, as well as the Cabinet Office in his view wrongly “fighting for a principle of confidentiality”. Amid tensions between Sunak and Johnson, the former prime minister was reported to police last week by Cabinet Office officials after the government-appointed lawyers found potential evidence of more lockdown-breaking parties in his diaries. Johnson has denied this. The prime minister and his predecessor were meant to have peace talks this week over issues such as the Covid inquiry and Johnson’s long-awaited peerages list but this phone call has been cancelled. Sources suggested this was related to No 10’s proposal for Oliver Dowden to be on the call, as Johnson’s team are said to blame the Cabinet Office minister for the leak of information that some of the former PM’s diaries were handed to the police. Sunak said on Tuesday the government was cooperating fully with the Covid inquiry and No 10 denied the suggestion of a cover-up. However, the government continues to resist handing over the material in advance of a new deadline of 4pm on Thursday set by Lady Hallett’s inquiry. The inquiry has also requested proof in the form of testimony from a senior official that the government does not hold any WhatsApp messages or notebooks from the former prime minister. It asked for records of searches conducted and correspondence with Johnson to be provided. The inquiry previously issued rulings requiring notebooks, diaries and messages between Johnson and 40 other senior government figures. It also requested copies of messages on devices held by his then adviser Henry Cook, and the same list of figures. However, the Cabinet Office has been considering whether to contest the request in the courts. Hallett has demanded the full cache of messages and diaries be handed over to the inquiry two weeks before the first public evidence sessions. But lawyers for the Cabinet Office are said to have advised that the inquiry does not have the powers to request access to all documents, raising the prospect of legal arbitration and a potential judicial review. Launching a legal challenge against the ruling by the head of a public inquiry would be unprecedented, sources said. Government insiders have said handing over Johnson’s unredacted notebooks and WhatsApp messages from him and Cook would be an affront to their privacy and the right to private policy discussion. A notice from the inquiry said on Tuesday: “The inquiry was informed that the Cabinet Office does not have in its possession either Mr Johnson’s WhatsApp messages or Mr Johnson’s notebooks, as sought in the original section 21 notice. “The notice has been varied so that if the Cabinet Office maintains its position that it does not hold specified materials, it must provide in substitute a witness statement from a senior civil servant, verified by a statement of truth. “This statement must specify that the Cabinet Office does not have in its custody or under its control the specified WhatsApp materials, or any copies thereof, and a record of searches that have been made, as well as a chronology of correspondence with Johnson or his office, regarding the identification of potentially relevant WhatsApp materials held by him. “The inquiry is also asking to know whether the Cabinet Office has had in its possession or under its control any of the requested materials and whether the potentially relevant messages held by Johnson are on a personal device or a Cabinet Office/No 10 one.”