A new attempt will be launched next week to force publication of the full report into whether No 10 parties broke Covid laws, with Conservative MPs urged to support the move to ensure there are “no more cover-ups and no more lies”. While more questionnaires were sent out by Scotland Yard to those who attended a dozen gatherings under investigation, a “humble address” motion was tabled in the House of Commons by the Liberal Democrats. If passed, ministers would be forced to release a specific set of documents within two days of the Met concluding its investigation. A date has yet to be set for the vote, but could come on the next opposition day allocated to the Lib Dems. It also emerged on Wednesday that the former major Tory donor John Armitage is now funding some staffing costs for the Labour frontbencher Wes Streeting, in an escalation of his opposition to Boris Johnson. Armitage, who revealed last week he had lost confidence in Johnson after giving £3m to the Conservatives, has donated £15,000 to the running of Streeting’s office. He previously donated £12,500 to Labour in March last year and £60,000 to the former MP Frank Field in 2016 and 2017. He also donated £65,000 to the remain campaign. The papers being demanded include an unredacted version of Sue Gray’s report, all accompanying evidence collected by the Cabinet Office, and a list of Downing Street staff issued with a fixed penalty notice. The move will reignite pressure on the government over the Partygate scandal, which has resulted in calls from some Tory MPs for Boris Johnson to resign. Despite the prime minister having attended some of the events under scrutiny, including a “bring your own booze” garden party organised by one of his most senior former civil service advisers, he has continued to deny any wrongdoing and has avoided a no-confidence vote. There are concerns that some details may never be known, after a leaked Whitehall memo to those investigated by Gray said the Met “will not make public the details of their investigation and therefore your line manager will not be notified”. The Lib Dem’s humble address motion was tabled and backed by all 13 of the party’s MPs. Ed Davey, the party leader, said Johnson “can’t be trusted to admit whether he or any other Conservative ministers end up being fined by the police”, and “we’ve seen time and again that his instinct is to lie, blame others or cover up the truth”. He added: “MPs from across all parties need to come together and force Boris Johnson to come clean. The public deserves to know whether our prime minister has broken the law, and for the full Sue Gray report, including any photos, to be published. “If Johnson is found to have broken the law, he must fess up and resign. No more cover-ups, no more lies.” Labour’s next opposition day is on 23 February, meaning that if the Met investigation has concluded by that point, Keir Starmer could table his own humble address motion to force the publication of documents related to the Gray inquiry. Angela Rayner, Labour’s deputy leader, has meanwhile written to the Cabinet Office minister Steve Barclay and the cabinet secretary, Simon Case, demanding a reassurance that Johnson and his staff have not been receiving any taxpayer-funded legal advice. Downing Street also admitted this week that no minutes were taken at the garden party attended by Johnson on 20 May 2020 that he said he thought had been a “work event”. A freedom of information request that asked for a record of discussions yielded no response, with No 10 pointing to government rules that say minutes do not need to be kept for some events, including those that are “purely informal or of a social nature”. Johnson has refused to say whether he would step down if fined by the police for breaking Covid laws but his spokesperson has suggested Downing Street will reveal if the prime minister does get a fixed penalty notice. This article was amended on 17 February 2022. Due to an editing error, an early version referred to Frank Field as the “the late” former MP. We apologise for this.