Conservative MSP John Lamont has resigned from the Scottish Parliament to contest the forthcoming UK general election.

Lamont is standing in the Berwickshire, Roxburgh and Selkirk Westminster constituency, a seat which he has contested at three previous elections.

A by-election will now be held to elect his replacement in the Scottish Parliament's Ettrick, Roxburgh and Berwickshire seat.

Lamont, who acts as the party's chief whip at Holyrood, hopes to unseat SNP MP Calum Kerr in the snap election.

Kerr won the seat in 2015 by just 328 votes ahead of Lamont.

Former Labour MP Ian Davidson has also announced his candidacy for the seat.

Holyrood's rules do not forbid MSPs from running for election at Westminster but Lamont has chosen to resign anyway.

Lamont said: "I want to continue that service to the Borders as a member of parliament and my approach to this important job will be exactly the same as it has been.

"This is one of the most important general elections Scotland has ever had. In the Borders, it will be straight fight between myself and the SNP.

"I have decided to stand down as an MSP to allow me to focus all of my energy on this important contest and to ensure that the electorate have a clear choice between the two contenders."

Scottish Conservative leader Ruth Davidson said he has built a "formidable reputation" at Holyrood over the last decade.

Three other Conservative MSPs, the party's sole Scottish MEP, are standing in June's election.

Neither of the four has so far indicated that they will resign before the election or if they are successful.