Alister Jack is sole Scottish Tory supporting Boris Johnson

David Duguid has resigned from his government roles, saying the Prime Minister’s position is “now untenable”.

It leaves Alister Jack, the Scottish secretary, as the sole Scottish Conservative MP who supports Boris Johnson.

Scottish Tory leader Douglas Ross earlier told the PM his “time is up”, having last month voted against Johnson on the vote of confidence.

Fellow MPs John Lamont, Andrew Bowie and David Mundell also voted against the Prime Minster, but Duguid and Jack voted in support.

In a fresh statement in the last hour, Duguid said: “In light of recent events, I believe the Prime Minister’s position is now untenable.

“Having indicated my concerns internally earlier this week, it is my intention to stand down from my position as fisheries envoy and trade envoy for Angola and Zambia.”

Ross earlier told STV: “I think we have seen that the Prime Minister must now know that the time has come for him to step aside.”

The Scottish secretary yesterday reconfirmed his support for Johnson. He said: “I am sorry to see good colleagues resign, but we have a big job of work to do, and that’s what we’re getting on with.”

Jack’s parliamentary private secretary, Ruth Edwards, resigned her position earlier.