Boris Johnson could face the prospect of another no-confidence vote within a year after Graham Brady, chair of the 1922 Committee, refused to rule out changing the rules. Some Tory rebels hope that after the prime minister faced calls from 41% of his own MPs to quit, a second bid to depose him could come sooner than expected. Under the current rules of the 1922 Committee, a leader who wins a no-confidence vote is immune from facing another one for 12 months, meaning Johnson is likely to remain leader of the Conservatives until at least June 2023. However, the committee’s 18 officers are able to change the rules and cut the immunity period to six months or less. Some officers are keen to pile pressure on Johnson and would support reducing the time before he can be challenged again, but are biding their time and waiting for what they believe are the next two most dangerous moments for him. This month’s byelections in Wakefield and Tiverton and Honiton, which the Conservatives hold but are expecting to lose to Labour and the Liberal Democrats respectively, are likely to be used as ammunition by the prime minister’s critics to argue he is no longer an electoral asset and that the party faces a wipeout at the next general election. Another investigation into law-breaking parties in Downing Street by the privileges committee will begin shortly, with MPs expecting it to report in the autumn. The committee’s evidence gathering could involve interviewing Johnson as part of their inquiry into whether he misled parliament by repeatedly insisting no Covid rules were broken, generating further embarrassing coverage with potential sanctions recommended if it finds against him. While Brady said it was unlikely the rules would be changed to allow another no confidence vote in Johnson before next summer, he left the door open to the possibility. “It’s not something that we as an executive have discussed at all in this parliament,” Brady told Times Radio. He said that after Theresa May won a no-confidence vote launched against her by a bigger margin, the committee did consider changing the rules but eventually decided against doing so. “I’ve reflected quite a lot on this because of the amount of speculation [there] has been in the media,” Brady continued. “Of course, it is technically possible that laws can be changed in the future. And it’s possible that rules can be changed in the future. But I think it’s important we say the rule that is in place, and is likely to remain in place is that there is a year’s period of grace following a confidence vote.” Even if the committee decides not to change the rules again, former Conservative leader William Hague warned that Johnson could be ousted in other ways. “One way or another, when you’ve got that level of disaffection in your own party, it won’t end well,” he told the House magazine. “I don’t know how it will end, but it will end in some sort of car crash in the cabinet, or some revolt of the activists, or a change in the rules to have another leadership ballot, or an election defeat. It will end badly.” Hague added that “when one can see something is going to end badly, you have to do something and take responsibility as the leader to do whatever you need to do, even if that includes getting out of the way”. Johnson has still retained the public support of his top team, with only two resignations – John Lamont as a ministerial aide and John Penrose as anti-corruption tsar. Michael Gove said he continued to back the prime minister enthusiastically. “If you’ve been in politics for a little while, as I have been, then there are always mistakes that you can look back on,” the levelling up secretary said. “But I think the prime minister is doing a good job.” Gove also stressed he would not run against Johnson again for the leadership, and urged rebellious colleagues to “demonstrate that the government is focused on delivering for the people across the UK”.