Downing Street has been accused of holding back report into alleged Russian interference in UK democracy.

The former head of MI5 has backed calls for a parliamentary report into alleged Russian interference in the UK democratic process to be published before the general election.

Downing Street has been accused of holding back the report by the Intelligence and Security Committee (ISC) after indicating it would not be cleared for release before Parliament is dissolved on Wednesday.

However, Lord Evans of Weardale, who was MI5 director-general until 2013, told BBC Radio 4’s Today programme that if ministers were not prepared to release it, they should explain why.

“In principle, I think it should be released,” he said.

“Part of the reason for having an Intelligence and Security Committee is that issues of public concern can be properly considered and the public can be informed through the publication of the reports once they have gone through the security process.

“If the government have a reason why this should not be published before the election, then I think they should make it very clear what that reason is.”

On Monday the prime minister’s official spokesman indicated the necessary clearance process has yet to be completed.

“There are processes reports such as this have to go through before publication. The committee is well-informed of these,” the spokesman said.

The ISC oversees the work of the agencies – MI5, MI6 and GCHQ – and in the course of its work has access to highly sensitive intelligence material.

Its reports are submitted to the government before publication to ensure no sensitive information is inadvertently made public.

Dominic Grieve, the chairman of the Parliamentary Intelligence and Security Committee (ISC), has said the process was normally completed within 10 working days.

However, this was disputed by government sources who said that it usually took six weeks.

Grieve has expressed concern that the report – which is reported to have looked into whether Russian interference affected the result of the 2016 EU referendum – contained information “germane” to voters in the forthcoming election.