Dominic Raab declined to confirm that Sue Gray’s report into the alleged Downing Street parties will be published in full next week, saying how much detail is made public will be Boris Johnson’s business.

In what appeared to be a reduction in the government’s commitment to being open about the report, Raab, the justice secretary and deputy prime minister, promised there would be “full transparency”, but refused to give details.

Gray, the senior civil servant tasked with investigating allegations of lockdown-breaking parties in Downing Street and elsewhere in government, is expected to release the report in the coming week.

Asked if the public would be able to see it in full, Raab told BBC One’s Sunday morning show: ‘Absolutely, the process will be up to the Prime Minister to decide. But the transparency will be total. He said he would come back to the House of Commons and make a statement, so there will be scrutiny.

Pressed on whether that meant it would be fully published, Raab said: “I’m not entirely sure what shape and form it will take, but the Prime Minister has been clear there will be full transparency about it, so people can see. We welcome that transparency, we have to learn from it.

It has been reported that Gray’s investigation has been widened to look at allegations that Johnson and his wife, Carrie, hosted parties at their flat above 11 Downing Street. According to the Sunday Times, Gray is investigating whether visits to the flat during the lockdown by government aides who are close friends of Carrie Johnson were necessary for the job.

Raab declined to say whether Gray was considering this, but agreed that Johnson should resign if he had misled parliament on the party issue.

“The interest for Sue Gray to conduct this investigation is that she can watch without fear or favor what she wants to watch, and we avoid trial by the media or the soap opera of things that come out unsubstantiated,” said Raab when asked. on new claims.

“What I would say about all of this is if it’s important, it’s important, Sue Gray should look into it.”

When asked if Johnson should go if parties were held in the apartment, Raab said he would not answer “hypothetical questions”, but added: “We have made it clear that the code of Ministerial conduct is there for everyone, including the prime minister.”

Pressed on whether Johnson should leave if he lied in the Commons, he said: ‘The code of conduct for ministers is very clear, that if you mislead Parliament it’s a matter of resigning.’

Speaking earlier, former Labor Prime Minister Gordon Brown said it seemed unlikely that Johnson’s career would “end in anything but scandal”.

“I fear scandal will follow Boris Johnson as long as he is prime minister,” Brown told Sky’s Trevor Phillips on Sunday.

“We don’t just have the scandal – and full details will probably come out later this week on the party – we have the conflicts of interest, we have the questionable dates, we have foreign money and points. question marks about who pays the bills for what, and I don’t think we’re going to see this administration end in anything but scandal.