Senior Scottish Tories want a vote of no confidence in Boris Johnson as soon as possible amid fears that voter anger over "partygate" will become "normalised" if he clings on.

       Party insiders told The Telegraph they believed an early vote, rather than waiting for the Metropolitan Police inquiry to conclude and the full Sue Gray report to be published, would have the best chance of ousting the Prime Minister.

       They are concerned that Mr Johnson will be able to remain in 10 Downing Street if the process is dragged out for weeks and voter anger starts to abate in the meantime.

       One insider said they "don't want the fury over 'partygate' to become normalised" or for people to "start shrugging their shoulders when the Prime Minister misbehaves".

       A drawn-out process would create a difficult situation for Douglas Ross, the Scottish Tory leader, the first senior Conservative Party figure to urge Mr Johnson to resign.

       It is understood Mr Ross will tackle his future relationship with Mr Johnson head on in a speech shortly – possibly his keynote address to the Scottish Tory conference next month. The Prime Minister is not expected to attend the two-day gathering in Aberdeen, the first time a UK Tory leader will not have been invited to address the Scottish conference.

       Scottish Tory MPs told The Telegraph they had received hundreds of emails and letters from constituents furious about the parties held in Downing Street during lockdown. Many constituents warned that they would not vote Conservative again while Mr Johnson remained leader.

       Another wave of correspondence arrived in their inboxes on Monday night and Tuesday after protesters targeted Sir Keir Starmer, the Labour leader, in Westminster. Some were heard shouting about Jimmy Savile.

       Mr Johnson has refused to apologise for claiming that Sir Keir failed to prosecute Savile when he was director of public prosecutions.

       Mr Ross is so far the only one of the six Scottish Tory MPs who has gone public to say he has submitted a letter of no confidence to Sir Graham Brady, the chairman of the 1922 committee.

       Alister Jack, the Scottish Secretary, has given Mr Johnson his total support. Three other Scottish Tory MPs – Andrew Bowie, David Mundell and David Duguid, have said they want to wait for the full Sue Gray report.

       However, The Telegraph understands that some Scottish Tory MPs are keen to see a vote of no confidence held quickly and want colleagues from across the UK to get their letters in now. A total of 54 must be submitted for a vote to be triggered.

       Although there is widespread scepticism among senior Scottish Tories that Mr Johnson could lead the UK party into another election, they fear he could cling on for months and potentially years.