Conservatives fear they could suffer major losses in the local council elections, as early signs show Labour making significant early gains in England.
Senior Tory sources warned voters may be staying at home in vast numbers due to fury over the prime minister repeatedly breaking lockdown rules.
Recent polling indicated Douglas Ross’ party could fall behind Labour in Scotland after a more successful election in 2017.
In England, Keir Starmer’s party has gained three key London borough councils and the Tories also losing seats in the Midlands.
The Lib Dems have also improved their vote share across areas in England as the Tories suffer the backlash from partygate.
Perth and Kinross councillor Chris Ahern told the Politico website that Conservative election hopefuls had been “dropped in it” by Boris Johnson.
Another source told The Times: “There are a sizable number of Tory voters who are staying at home because of anger at Boris and partygate.”
Early results from wards across Scotland show the share of first preference votes for the Conservatives down from 2017.
The Tory vote in Angus ward Kirriemuir and Dean has plummeted by 16.5% as the party lost one of their seats.
Elsewhere, their vote in Perth and Kinross ward Carse of Gowrie is down by 6.8% compared to five years ago.
Douglas Ross has repeatedly insisted the Tories would be able to hold onto second place.
A bad performance after the vote count could see them lose control of key councils in mid-Scotland and the north-east.
‘Difficult results’
The Scottish Tory chief originally called for the prime minister to resign over his repeated lockdown breaches.
However, he later insisted Mr Johnson should remain in his post due to the ongoing war in Ukraine.
Conservative minister Oliver Dowden admitted the party had suffered some “difficult results” south of the border.
But he insisted the Tory leader remains the right man to lead the party into the next general election.