Alex Salmond has weighed into the row over Douglas Ross and his hospitalised colleague David Duguid describing the Scottish Conservative leader as "Dick Dastardly" after the TV villain cartoon character.

Mr Ross announced yesterday his intention to stand as his party's candidate in Aberdeenshire North and Moray East in place of former Tory minister Mr Duguid who has been undergoing hospital treatment since April 11.

The Scottish Conservative management board – which Mr Ross is a member of – ruled earlier this week that ill health meant Mr Duguid should not stand for election on July 4 prompting Mr Ross to U turn on his decision not to stand as a general election candidate and to say he intended to be the candidate for the new north east seat.

However, Mr Duguid has disputed that claim saying he is well enough to be the party's candidate for the seat.

In his speech at Alba's general election launch today, Mr Salmond, who lives in Aberdeenshire, said the Conservatives were on a path of "self destruction" as he brought up the controversy about Mr Ross and Mr Duguid.

He also attacked Prime Minister Rishi Sunak for leaving events early to mark the 80th anniversary ceremony to mark the D Day landings to return to the UK to do a TV interview over his misleading claim Labour would increase tax by £2,000 a year describing him as "Muttley", Dicky Dastardly's dog and side sick. 

The UK statistics watchdog later said anyone who heard Mr Sunak say Labour would raise taxes by £2,000 per working household would have no way of knowing that was a sum totalled over four years.

"Douglas Ross is the Dick Dastardly of politics to shove aside a wounded colleague [for his own advancement] someone literally on their hospital bed so they can grab their seat," he said.

"Incidentally that is where I stay and behaviour like that is not tolerated. But if Douglas Ross is Dick Dastardly, then the Prime Minister must be Mutley to leave D Day veterans to rush back to London for a political interview to explain why you were lying in the first [TV] debate.

"Everyone in the country knows there are lies, damned lies and statistics. To snub D Day veterans on the 80th anniversary.. someone who does that, is not fit to be a politician never mind fit to be a Prime Minister.

"The Tory party descent into self destruction laid bare."

Later, taking questions from journalists, Mr Salmond said he knew Mr Duguid saying he was "well liked" and a popular MP and that Mr Ross would "get his comeuppance".

He added: "[David Duguid] is not particularly party political in parliament, I don't mean any disrespect in that. David is not aggressively party political. 

"So to shove aside somebody who clearly wanted to stand in the campaign - many MPs have campaigned in their hospital beds before - you stand on your record over previous years, you don't have to be on the doorstep in an election campaign. To be shoved aside in a disgraceful manner. I thought I had seen everything in politics. But I have not seen anything so blatant and Douglas Ross is going to get his comeuppance."

Mr Ross made the announcement that he was intending to stand in Aberdeenshire North and Moray East despite having previously said he would quit Westminster to focus on Holyrood and his post as leader of the Tories, Mr Ross – who is also an MSP for the Highlands and Islands – announced on Thursday that he will stand in the seat.

Defending his decision on Friday, Mr Ross said: “I want to lead from the front, this is a really important seat.”

Mr Salmond is the latest party rival to attack Mr Ross's decision.

Speaking earlier First Minister John Swinney said ousting Mr Duguid was “no way to treat another human being”.

He said the SNP’s chances of winning the seat are now “a great deal better” because of Mr Ross’s decision.