RUTH Davidson has quit as leader of the Scottish Tories, saying the thought of fighting elections and being away from her son fills her with "dread".

In a letter to Robert Forman, the party’s chairman in Scotland, she insisted her decision to leave was personal and not political.

“I have to be honest, where once the idea of getting on the road to fight two elections in 20 months would once have fired me up, the threat of spending hundreds of hours away from my home and family now fills me with dread," she said. "That is no way to lead.”.

She added: “I fear that having tried to be a good leader over the years, I have proved a poor daughter, sister, partner and friend. The party and my work has always come first, often at the expense of commitments to loved ones. The arrival of my son means I now make a different choice.”

The outgoing Tory chief also insisted she remained loyal to Boris Johnson.

“Be assured, “ she told Forman, “I will continue to support the party, the Prime Minister and Scotland’s place in the United Kingdom from the backbenches and beyond.”

Her spokesman told journalists that Davidson had first voiced doubts about the job after May's European Election when the Tories finished in fourth place behind the Brexit Party and the Lib Dems.

He said she had spent the summer considering her position and had decided to quit. He insisted the timing - coming out on the day the government prorogued parliament - was coincidence.

Davidson had often been tipped as a future Prime Minister - though she always insisted her ambition was to be a future First Minister.

In a press conference, the Tory said her proudest achievement was campaigning against independence

"For me, electoral successes – while undoubtedly important – pale in significance compared to the vital role our party undertook as part of the campaign to keep Scotland in the United Kingdom at the independence referendum.

"It was – without doubt – the most important contribution of my working life and, I believe, will remain so."

After he became Prime Minister, Davidson said she would not support Johnson if he pursued a no deal Brexit.

Writing in the Mail on Sunday, she said: "I hope beyond measure the new Prime Minister is successful in getting an agreement with the EU so he can go back to the House of Commons and get the majority backing he needs. He has my full support in those efforts.

"Where I differ with the UK government is on the question of a no deal Brexit.

"When I was debating against the pro-Brexit side in 2016, I don't remember anybody saying we should crash out of the EU with no arrangements in place to help maintain the vital trade that flows uninterrupted between Britain and the European Union.

"I don't think the Government should pursue a no deal Brexit and, if it comes to it, I won't support it."

The MSP was said to be furious when Johnson ignored her advice and sacked David Mundell as Secretary of State for Scotland.