NICOLA Sturgeon says Ruth Davidson has reclaimed her own independence after she resigned as Scottish Tory leader.

Speaking to Sky, the First Minister said it was an "open secret" that there were "political factors" in Davidson's decision.

"It's an open secret that there are probably political factors in this decision as well. Her disagreements with Boris Johnson are well known and I think it has been obvious for some time how uncomfortable she has been in trying to defend his leadership and the direction that he's taking the UK in particularly over Brexit.

"I guess it does pose a bigger question, if we're in a situation now where the leader of the Scottish Conservatives can't reconcile herself to the extreme hard Brexit driven leadership of Boris Johnson then why should the rest of Scotland have to reconcile ourselves to that.

"Ruth has reclaimed her own independence today.”

READ MORE: Nicola Sturgeon: This was the day independence became inevitable

Scottish Labour leader Richard Leonard credited Davidson with the "increase in support for her party in Scotland".

He added: "Her departure as leader will be a massive setback for them. However, the timing can be no coincidence and shows clearly that Boris Johnson's conduct as Prime Minister isn't acceptable even to those who share his politics.

"I wish Ruth and her family all the best for the future."

In a personal message, shared on twitter, LibDem leader Jo Swinson said: "Our politics are different Ruth, but I have always admired your kick-ass approach, breaking glass ceilings and challenging the old guard. Wishing you & Jen all the best – enjoy all those magical moments with baby Finn"

Meanwhile, Scottish LibDem leader Willie Rennie said the Tories could struggle in Scotland without Davidson.

"There is little doubt that Ruth Davidson has brought a spark of life to the Conservatives and to Scottish, even UK politics, at a time that it really mattered," he said.

"Often I found her fun to work with where we agreed and a formidable opponent when we didn't. She can leave the stage in the knowledge that she played her part and played it well."

But he added: "The Conservatives know that her absence is a problem for them as they will struggle to speak for the hundreds of thousands of people with moderate views who want Scotland in the heart of the UK and reject Boris Johnson's cavalier approach to running our country."

Journalist Tom Peck tweeted: “A terrible shame Ruth Davidson has decided she cannot balance the commitments of both a political career and a family. Boris Johnson manages it, and he has at least three."

READ MORE: Ruth Davidson formally resigns as Scottish Tory leader

Prime Minister Boris Johnson, tweeting more than two hours after the resignation was confirmed, paid tribute to Davidson, saying: "On behalf of everyone in the Conservative and Unionist Party, I want to thank Ruth for her wonderful service over the last eight years.

"She has dedicated so much time and energy to the role and has been instrumental in the revival of our electoral fortunes in Scotland.

"She should take immeasurable pride in the pivotal role she played during the Scottish independence referendum campaign, where her passionate support for our Union was crucial to the result."

He added: "I will miss the incredible leadership she has given to our party in Scotland, but I am delighted that she will continue to use her enthusiasm, passion and dedication to make the case for Scotland's place in the United Kingdom from the backbenches and beyond.

"I wish Ruth, Jen and Finn all the best for the future."