Mr Jack said Boris Johnson welcomed the investigations, and added: “He was very apologetic yesterday for what happened on his watch.
"He doesn’t seem to pass the buck on that. He understands people made huge sacrifices throughout the pandemic, and he, as I say, he was very sincere in his apology.”
Mr Jack said there a number of events where Mr Johnson was not present, adding: “When the cat’s away, the mice were playing.”
“He was appalled by those events and he was furious, as he said at the dispatch box. But he has subsequently learned from them, as have others, obviously Sue Gray, and he has said action will be taken, he’s very clear about that.”
Challenged that in fact Mr Johnson was at the events, Mr Jack said: “He was very clear that the events he attended were, he believed, to be work events as much as they were saying goodbye to a colleague or thanking colleagues for the efforts during the pandemic, and he’s made that clear from the dispatch box.”
His comment comes after Jacob Rees-Mogg called the Scottish Tory leader a ‘lightweight’ after Mr Ross called for Johnson to resign.
Mr Jack told the BBC’s Good Morning Scotland: “I want the right person to run this country and I believe Boris Johnson is an excellent Prime Minister. I work very closely with him.
“I think Douglas is an excellent leader of the Scottish Conservatives, holding Nicola Sturgeon to account. I am very happy with both of them carry on in the roles.”
Mr Jack added: “Douglas Ross is appointed into his role by the members of the Scottish Conservative Party – that is a completely devolved organisation with its own constitution. His position is quite secure.