Scottish Secretary Alister Jack has confirmed he will stand down as an MP at the next general election.
However he left the door open to accepting a peerage and entering the House of Lords after that point.
The Dumfries and Galloway MP said he would definitely not accept the peerage while still sitting as an MP, which would trigger a by-election.
In an interview with ITV Border, he said his UK Government role is an “enormous privilege” which he intends to continue in until the next election.
Mr Jack said: “I’m not going to the House of Lords and causing a by-election.”
Asked if he would go to the Lords if he stood down at the next election, he replied: “Who knows?”
Mr Jack continued: “I’ve been very clear in saying that I will not be standing at the next general election.
“I said that to Boris Johnson, I’ve said that to Liz Truss when she appointed me as secretary of state for Scotland.
“And I said it to Rishi Sunak when he also appointed me as Secretary of State for Scotland.
“At each reshuffle I’ve said ‘I want to be honest with you, I’m not standing at the next general election’.
“But they’ve factored that in and given me the privilege of continuing to serve.”
He said his local party will seek to find a new candidate “in the next couple of months”.
First elected to the Commons in 2017, Mr Jack took up his current Government role in July 2019, succeeding David Mundell as Scottish Secretary.
The SNP said Mr Jack should immediately stand down from his Dumfries and Galloway seat.
The party’s deputy Westminster leader Mhairi Black said: “Alister Jack must come clean on whether he’s done a sleazy backroom deal with Rishi Sunak to delay his peerage in order to avoid another by-election defeat for the Tories.
“The SNP is the main contender in Dumfries and Galloway, and every Tory-held seat in Scotland.
“We are ready to take the fight to the Tories – and challenge Alister Jack to stand down now, so people in Dumfries and Galloway can have an SNP MP that will stand up for their interests, instead of rubber-stamping every damaging decision from Downing Street.
“Voting SNP is the best way to beat the Tories in Scotland at the next election – and is the only way to get rid of Westminster Tory governments for good with independence.”