Boris Johnson has been accused of presiding over a cover-up as it emerged a report on alleged Russian interference in British politics will not be published until after the election.

It has gone through the standard security clearance process, but Downing Street indicated that it would not allow the potentially incendiary 50-page dossier from the intelligence and security committee to be published immediately.

The report was expected to include evidence rom UK intelligence services over covert Russian attempts to influence the outcome of the 2016 EU referendum and 2017 general election.

Ex-terrorism watchdog Lord Anderson said any further delay would "invite suspicion" of the government's motives in the run-up to next month's election.

READ MORE: Issue of the Day - Fears over electoral interference by Russia

The committee’s chairman, Dominic Grieve, called the decision “jaw dropping”, saying no reason for the refusal had been given, while Labour and Scottish Nationalist party politicians accused No 10 of refusing to recognise the scale of Russian meddling.

The Herald: Putin spoke at the opening of an arms show at a shooting range in Alabino just west of Moscow

Ministers said the report, which examines Russian activity including allegations of espionage, subversion and interference in elections, would be published "in due course" in line with procedures for "sensitive" information.

The report, written by Parliament's Intelligence and Security Committee, was finalised in March and referred to No 10 on October 17.

The usual 10-day wait for release has passed, and if it is not published before Parliament dissolves on Tuesday it will not be published ahead of the election.

A No 10 spokesman added: “There are processes reports such as this have to go through before publication, and the committee is well-informed of these.”

Mr Grieve said “The protocols are quite clear. If the prime minister has a good reason for preventing publication he should explain to the committee what it is, and do it within 10 days of him receiving the report. If not, it should be published.

He added: "We continue to be very disappointed by the failure of the government to publish this report and to provide any explanation as to why it should not be published. Explanations currently advanced that the timing are too short are entirely disingenuous and grossly misleading."

At the weekend Labour demanded that the Prime Minister's most senior adviser, Dominic Cummings, answers a series of questions relating to his past in Russia after a whistleblower allegedly came forward with “serious concerns”.

READ MORE: Is Dominic Cummings really the most dangerous man in Europe?

In a letter to Dominic Raab, Emily Thornberry queried whether the former Vote Leave director has been granted access to some of the government’s most sensitive “top secret” files.

The shadow foreign secretary said an “official-level whistleblower” had raised “serious concerns” with members of Jeremy Corbyn’s front bench regarding Mr Cummings’ time in Russia in the 1990s after graduating from university.

Copying in the civil service chief Sir Mark Sedwill, and members of Britain’s security services to the correspondence, Ms Thornberry said Labour did not “know the veracity of their claims” but felt compelled to inform them.

The Cabinet Office said: "We do not comment on individuals' security clearance."