The chairman claims that the draft of the 50-page dossier was sent to Downing Street on 17 October.
"Parliament and the public ought to have, and must have, access to this report in light of the forthcoming election, and it’s really unacceptable for the prime minister to sit on it and deny them that information," Grieve said, as quoted by The Guardian newspaper.
According to The Guardian, the dossier looks into the assertions that Moscow was supporting Brexit behind the scenes during the 2016 referendum by funneling money into UK politics at the time, the Conservative party in particular, and waging an influence campaign. The dossier targets several individuals, one of whom is Arron Banks, who provided financial support to Nigel Farage, one of the key figures in pro-Brexit politics.
Earlier this month, Farage's Brexit Party dismissed a European Parliament resolution on countering foreign election meddling and alleged Russian interference as "baseless propaganda".
The British government has repeatedly accused Russia of interference in the 2016 referendum, though failing to provide any exact evidence.
In 2016, the United Kongdom voted to leave the European Union on 29 March 2019. After former PM Theresa May had to resign failing to pass her departure deal in the Commons, Boris Johnson won the Conservative leadership by promising to deliver Brexit by any means necessary and replace the controversial Irish Brexit negotiated by May.