Boris Johnson is “fit for office”, Scottish Conservative leader Douglas Ross has said amid continued criticism over parties in and around Downing Street during lockdown.

The British prime minister has been under pressure in recent weeks after he – along with his wife Carrie Johnson and Chancellor Rishi Sunak – received a fine for one of the gatherings.

Mr Ross, who had previously called on Mr Johnson to quit before the Russian invasion of Ukraine, has backed the prime minister.

He had submitted a letter to the backbench 1922 Committee (a right-wing grouping within the Tory party) pushing for a vote of no confidence in him but has since rescinded it.

Speaking to the Scotsman, Mr Ross was asked if the the prime minister was fit for office.

He said: “Yes, because he is leading the UK response to this crisis at the moment.

“But that doesn’t in any way diminish what he did and the actions that have been taken by those who investigate it.

“He is fit for office to continue with what the UK government have done, his government has done, to help the people of Ukraine.

“That’s not just me saying it, that’s President (Volodymyr Zelensky) who singled out Boris Johnson as a western leader who has provided some of the greatest support.

“(SNP Westminster leader) Ian Blackford stood up in the House of Commons and called for unity. I agreed with them when they said that.”

Nicola Sturgeon said the Scottish Tory leader’s comments show a “lack of principle” and “consistency”.

During a campaign visit to Barrowfield Community Centre in Glasgow yesterday, Scotland’s First Minister said Boris Johnson should have “resigned already”.

She said: “I don’t think he’s fit for office and it’s not that long ago that Douglas Ross said he wasn’t fit for office and he should resign.

“Douglas Ross doesn’t appear to be able to hold to one opinion for more than a couple of days at a time.

“It just shows, I think, a lack of real principle. A lack of real resolve and consistency.” 

However, Ms Sturgeon said the problems with the Conservatives span beyond Mr Johnson’s leadership.