“Disgusting and misogynistic” WhatsApp messages between Boris Johnson and Dominic Cummings have been disclosed to the Covid inquiry, according to the former Conservative chancellor George Osborne. Cummings, Johnson’s chief adviser when Covid struck, is due to appear before the inquiry for the first time next Tuesday. Speaking on his Political Currency podcast with Ed Balls, Osborne said he had been told that the latest messages shared with the inquiry contained foul and sexist language. He said: “From what I understand, there are some pretty staggering things that have been said on those WhatsApp messages … not just by Boris Johnson, but key advisers like Dominic Cummings. Really pretty disgusting language and misogynistic language.” The inquiry has already heard derogatory language used between Johnson’s advisers. Earlier this month it heard of the UK’s most senior civil servant, Simon Case, complaining to Lee Cain, Johnson’s then director of communications, about the power of Johnson’s then fiancee, Carrie Symonds, now his wife. Cain, who is due to appear at the inquiry on Monday, said Symonds “doesn’t know wtf she is talking about”. In another message, Case said: “I was always told that Dom [Dominic Cummings] was the secret PM. How wrong they are. I look forward to telling select cttee tomorrow – ‘oh, fuck no, don’t worry about Dom, the real person in charge is Carrie.’” Osborne suggested that worse language could emerge next week. He said: “I think we’re going to get some pretty astonishing and frankly shocking WhatsApp messages and the like being published from that Johnson period.” He said the messages would show “just what a complete nightmare it was for many people working in 10 Downing Street and who worked at the top of government at the time, and potentially some things that are going to cause some real problems for individuals who were in charge at the time.” Cummings and Johnson have not commented on Osborne’s remarks. Cummings has previously admitted that he referred to Johnson as a “complete fuckwit”. Earlier this month, the inquiry heard that Angela McLean, now the government’s chief scientific adviser, referred to another leading scientist, Carl Heneghan, as a “fuckwit”. Sources have previously denied that Cummings and Cain referred to Carrie Johnson as “Princess Nut Nut”, but it was reported that others in their circle did use the nickname. The Guardian revealed that Boris Johnson had told the inquiry he had been unable to access messages between 31 January and 7 June 2020, despite the phone being in action until the following spring. And Rishi Sunak has failed to hand over his WhatsApp messages from the time, claiming that he did not have access to the messages during his time as chancellor because he changed his phone several times. Other messages in a WhatsApp group containing Case, Cain and Cummings suggest the exasperation felt within Johnson’s inner circle at the government’s handling of the lockdowns. According to the Times, Case said Johnson was keen to roll back social distancing regulations and announce: “We’re over Covid.” In one message, the then head of the civil service described this behaviour as “Trump Bolsonaro levels of mad and dangerous”. With a second wave of coronavirus in Britain appearing imminent, plans for a large-scale reopening of the economy were eventually delayed until the middle of August. By November, the government had decided to impose a new lockdown. In another exchange, Case wrote: “Am not sure I can cope with today. Might just go home. Matt [Hancock] just called, having spoken to PM. According to Matt (so aim off, obvs), PM has asked Matt to work up regional circuit breakers for the north (as per Northern Ireland) today – and to bring recommendations. I am going to scream.”