Boris Johnson has cleared a controversial report into alleged Russian interference in UK politics for publication, Downing Street has announced.

The prime minister came under fire for blocking the release of the Intelligence and Security Committee report ahead of the general election, with ISC chair Dominic Grieve describing the decision as “jaw dropping”.

Mr Grieve, who lost his seat in Thursday’s election, told The Independent: “The fact that he has been able to sanction its publication now shows that in fact it was perfectly possible to sanction its publication before parliament was dissolved in November. The reasons he gave at the time for non-publication were bogus.”

The paper – believed to cover Moscow’s alleged efforts to exert influence in the UK through cash donations, political contacts and social media manipulation – cannot be published until the appointment of a new committee and is not expected to come before January.

The new ISC chair and members will be nominated by the prime minister in consultation with the leader of the opposition and approved by parliamentary vote, a process which is certain to take a number of weeks.

Boris Johnson and Brexit merchandise for sale at the Tory conference Show all 10 1 /10 Boris Johnson and Brexit merchandise for sale at the Tory conference Boris Johnson and Brexit merchandise for sale at the Tory conference A Boris Johnson doll for sale at the Conservative Party Conference in Manchester on 29 September PA Boris Johnson and Brexit merchandise for sale at the Tory conference Mugs with Boris Johnson's portrait for sale at the Conservative Party Conference in Manchester on 29 September AP Boris Johnson and Brexit merchandise for sale at the Tory conference A Boris Johnson themed T-shirt for sale at the Conservative Party Conference in Manchester on 29 September AFP/Getty Boris Johnson and Brexit merchandise for sale at the Tory conference Boris Johnson and other Conservative themed cards for sale at the Conservative Party Conference in Manchester on 29 September AP Boris Johnson and Brexit merchandise for sale at the Tory conference Boris Johnson posters for sale at the Conservative Party Conference in Manchester on 29 September EPA Boris Johnson and Brexit merchandise for sale at the Tory conference Copies of The Conservative newspaper are ready to be distributed during the Conservative Party conference on 30 September Getty Boris Johnson and Brexit merchandise for sale at the Tory conference "GET BREXIT DONE" mugs alongside other Conservative merchandise at the party conference in Manchester on 29 September PA Boris Johnson and Brexit merchandise for sale at the Tory conference Assorted Conservative merchandise for sale at the party conference in Manchester on 29 September PA Boris Johnson and Brexit merchandise for sale at the Tory conference Books about Jacob Rees-Mogg and Jeremy Corbyn for sale at the Conservative Party conference in Manchester on 29 September Getty Boris Johnson and Brexit merchandise for sale at the Tory conference A variety of books for sale at the Conservative Party conference in Manchester on 29 September Getty

Mr Grieve said he was concerned that it could be April or later before a new committee is able finally to approve the release of the report. The last time a new ISC was appointed, the process took nearly six months.

Unlike other parliamentary committees, the ISC reports to the PM, rather than the House of Commons or House of Lords, and Mr Johnson has the power to hold back publication of any report until he has determined that it does not breach national security.

Mr Johnson’s official spokesman told reporters: “In line with his responsibilities under the Justice and Security Act 2013, the prime minister carefully considered the report of the former committee.

“He is content publication would not prejudice the functions of those bodies that safeguard our national security. Publication will be a matter for the new ISC in due course.”

The spokesman declined to say when the PM reached his decision that the report could be published.

Mr Grieve has steadfastly refused to reveal any details of the contents of the report, which looks into claims that the Russian government influenced the outcome of the 2016 EU referendum and 2017 general election.

Unconfirmed reports suggested that nine Russian businesspeople who made donations to the Conservative Party are named in the document.

Completed in March, the report was passed to Downing Street on 17 October after being cleared for publication by intelligence agencies.

Speaking ahead of the election, shadow foreign secretary Emily Thornberry said the decision to withhold release was “clearly politically motivated”.

Bill Browder gave evidence to the inquiry (EPA)

But challenged in November over whether he was trying to cover up evidence of Russian influence, Mr Johnson said: “There is no evidence for that, and I think we have got to be very careful before we simply cast aspersions on everybody who comes from a certain country just because of their nationality.”

Witnesses to the inquiry included members of MI5, MI6 and the government’s eavesdropping centre GCHQ.

Others understood to have given evidence are US financier Bill Browder, a prominent critic of Vladimir Putin, and Christopher Steele, the former MI6 officer who compiled a dossier on Donald Trump’s links to Russia.

Mr Browder gave evidence about alleged links between Russian oligarchs and British politicians, submitting a dossier to the committee which claimed that many UK individuals and companies had taken money from Russia in return for information and advice.