What next for Boris Johnson over lockdown parties in Downing Street?

Boris Johnson told the Commons that he thought the “will of the people is to say thank you to Sue Gray and for us collectively to move on”. He hopes his “humble” apology will be the end of the matter – an apology for shortcomings for which he was responsible, even if, as he repeatedly reminded MPs, he wasn’t even present for most of them.

It may be. The Gray report failed to provide the evidence for which his critics were looking that would show he had knowingly misled parliament when he said “the rules were followed at all times”.

But that question has been referred to the Commons committee of privileges, which will take some time to deliberate, and Labour MPs think there are two other possible avenues of attack that are still open to them.

The first is the “Abba” party. The prime minister failed to give a definite answer to questions about whether he had had any discussions with Gray about changing or omitting anything in her report. She said in the report that she had started to investigate the alleged party in the prime minister’s flat in Downing Street to celebrate the departure of Dominic Cummings, but she dropped it when the police began their inquiries.

The police decided against issuing any penalty notices for that gathering, and Gray said: “I considered whether or not to conduct any further investigation into this event but concluded it was not appropriate or proportionate to do so.”

But she gives few details about the event – from which it has been reported that “The Winner Takes It All” could be heard elsewhere in the building – except that it was attended by five special advisers.

The second line of attack open to Johnson’s critics is the demand that the Metropolitan Police explain why it issued some people with penalty notices and not others. Gray’s accounts of the various gatherings and the photographs in her report of the “birthday party” in the cabinet room have only added to those questions.

Stephen House, the acting commissioner of the Metropolitan Police, will be appearing before the police and crime committee of the London Assembly on Thursday morning, at which he is likely to be asked whether his force will give any further information about the reasons for its decisions and the nature of the legal advice it has taken.

Finally, the inquiry by the committee of privileges is bound to keep the question of lockdown law-breaking in Downing Street alive, even if it is unlikely that it will conclude that the prime minister deliberately misled parliament. The committee has a Conservative majority, but all its members will want to demonstrate their independence and rigour – and they will no doubt make the most of their chance to question Johnson himself.

Its deliberations are likely to continue into the autumn, so although it may seem that the prime minister “has got away with it” (in the words of his former principal private secretary about the “bring your own booze” event in the Downing Street garden), the scandal still has some distance to run.