BORIS Johnson and Theresa May ignored claims Russia has a "likely hold" over Donald Trump and may have funded Brexit, a former spy has alleged.

Christopher Steele gave secret evidence to MPs who drew up the Kremlin report.

The MI6 veteran accused the government led by May and in which Johnson was foreign secretary for two years of refusing to acknowledge allegations about Trump because they were afraid of offending him.

Steele first presented a dossier about Trump to senior UK intelligence figures in late 2016, who he says took it seriously at first. But, he writes, “on reaching top political decision-makers, a blanket appeared to be thrown over it”.

“No inquiries were made or actions taken thereafter on the substance of the intelligence in the dossier by HMG [Her Majesty’s Government],” Steele says in the document.

The allegation is contained in a short summary of a larger file of information presented in August 2018 by Steele to parliament’s intelligence and security committee (ISC), inquiring into Russian infiltration into British politics and public life.

Steele accuses May’s government of selling British interests short by not taking matters further: “In this case, political considerations seemed to outweigh national security interests. If so, in my view, HMG made a serious mistake in balancing matters of strategic importance to our country.”

“A prospective trade deal should never be allowed to eclipse considerations of national security.”

Steele’s confidential testimony is revealed for the first time in a book by Guardian journalist Luke Harding, Shadow State: Murder, Mayhem and Russia’s Remaking of the West, to be published next week.

Downing Street said on Monday it could not comment on the Russia report or its evidence until it was published. 

The cross-party committee finished the report in October last year but Boris Johnson refused to publish it in the run-up to December's General Election. After the election, he cleared the report for publication in principle, but doing so would require the ISC to be reconstituted.

The committee is yet to be formed amid growing speculation that there is a row about who will chair it. No 10 has suggested it wants the former transport secretary Chris Grayling to do so.

But Downing Street needs the Tory nominees to the nine-strong committee to agree to support Grayling because the opposition minority want to vote for somebody else. In law the appointment of the chair is a matter for the committee. As a result the long-awaited document is still yet to be released, leading to the SNP, Labour and the LibDems to accuse the Tories of a cover-up.

“We increasingly think the real reason this is all being held up is because of No 10,” said an SNP source. The Lib Dem foreign affairs spokesperson, Alistair Carmichael, said the delay was “utterly reprehensible”.