RUTH Davidson is expected to replace Jackson Carlaw at First Minister's Questions after the Scottish Tory leader's resignation.

Conservative MP Douglas Ross is expected to take over from Jackson Carlaw who said he is not the best person to make the case for Scotland staying in the Union.

It is believed Ross could be placed top of his party’s regional list in the Highland and Islands to secure a place in the Scottish Parliament. Until then, it is believed that Davidson would take over at FMQs again – despite the party having two deputies, MSPs Annie Wells and Liam Kerr.

READ MORE: Douglas Ross rumoured to take over as Jackson Carlaw quits

A party insider told The Scotsman: “There was unhappiness within the group about the direction of the last few months, which was a bit unfair, and he also had to follow on from Ruth, which is a bit like taking over from Alex Ferguson – it was never going to be easy.

"The polls haven’t helped and Jackson is a genuine party man so he will have felt the burden of leadership heavily, and obviously decided he wasn’t the right person to lead in the battle ahead.”

READ MORE: Jackson Carlaw resigns as leader of the Scottish Conservatives

Another added: “There’s an election imminent and the polling is terrible and our members and activists are looking at George Galloway with whole new eyes... Labour can limp along with Richard Leonard but we’re not going to be in the same position.”

But another party source said: “This has blind-sided a lot of party folk usually in the know about these things. It’s not comparable to Ruth going as people knew that was happening - this has come from nowhere.”

Carlaw was elected leader in February, replacing Davidson.

In a statement, he said: "Over the summer I have had the chance to think hard about my role as leader of the Scottish Conservatives.

"Nothing is more important to me than making the case for Scotland's place in the United Kingdom.

“I believe the Scottish Conservative and Unionist party is the most important voice in Scotland for setting out that positive argument. I am clear that nothing must get in the way of doing so.

"In the last few weeks, I have reached a simple if painful conclusion – that I am not, in the present circumstances, the person best placed to lead that case over these next vital months in Scottish politics prior to the Holyrood elections. Given the importance I attach to the job, I've therefore decided to stand down with immediate effect."

READ MORE: 'Was he pushed or did he jump?': Twitter reacts to Jackson Carlaw quitting

Responding to the announcement, Boris Johnson thanked Carlaw.

He commented: “Jackson Carlaw has been a tremendous servant to the Scottish Conservative Party for more than four decades.

“As an activist, deputy chairman, deputy leader and leader, he has given his all and deserves our thanks for his efforts.

“It is a mark of his commitment to the cause that he chooses to stand aside at this time and I offer my best wishes to him, Wynne and the family.”

READ MORE: This is Boris Johnson's response to Jackson Carlaw quitting

Nicola Sturgeon sent her best wishes to the outgoing Scottish Tory leader.

READ MORE: 'We’ve crossed swords politically': FM reacts to Jackson Carlaw quitting