UPDATE: Ruth Davidson has now officially quit as leader of the Scottish Tories, saying the thought of fighting elections and being away from her son fills her with dread.

RUTH Davidson is set to announce today she is quitting as leader of the Scottish Conservatives.

According to reports yesterday, party insiders said she is to stand down from the top post because she’s “increasingly at odds” with Prime Minister Boris Johnson.

Davidson, who returned from maternity leave in April, has made no secret of her differences with the hardline Brexiteer who yesterday announced plans to suspend Parliament.

Writing in The National, First Minister Nicola Sturgeon attacked Davidson for failing to respond to Johnson plans to suspend Parliament. Nicola Sturgeon then went on to ask: “If she is no longer prepared to tolerate government by Boris Johnson then why should Scotland be expected to?”

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

The expected announcement by Davidson raised speculation about what her departure from the leadership role would mean for Scottish independence.

Chris Deerin, director of the Reform Scotland think tank, suggested Davidson’s resignation would weaken the Union. “There are some talented people on the Scottish Tory benches, but no-one with the energy, charisma and campaigning pizzazz of Ruth. If she is going, the Union loses its most effective advocate,” he tweeted.

The Scottish Labour MP Ian Murray also predicted bad days ahead for the Union.

Ruth Davidson is a formidable politician and her departure will be deeply felt by her party,” he said.

“She campaigned tirelessly for a Remain vote in the EU referendum, but the Tories under Boris Johnson have become a hard Brexit party, so it is not surprising that it has come to this.

“The Prime Minister and his allies are willing to crash the UK out of the EU without a deal, and they are no longer listening to voices of reason. Boris Johnson’s plan for a hard Brexit is a threat to the Union, and sensible Tories know this.”

READ MORE: Brexit: 'Dictator' Boris Johnson shuts down Parliament

Scottish Liberal Democrat leader Willie Rennie said: “It’s no surprise thatRuth Davidson has run out of reasons to stand by this dangerous and power-hungry Prime Minister.

“There must be lots of other like-minded Conservatives who are horrified at this blatant abuse of power and can’t stomach being party to this destructive agenda any longer. They should take this as the signal to abandon ship.”

The National: Chris Deerin of Reform Scotland said the Union will be losing its most effective advocate in Ruth DavidsonChris Deerin of Reform Scotland said the Union will be losing its most effective advocate in Ruth Davidson

A senior Conservative source said: “Ruth has been talking to senior party figures in the Conservatives for the last few weeks, both in Scotland and down south.

“She has been under huge pressure as a new mum. Nobody really fully understands how your life is going to change as a parent until it happens. Ruth is no different in this respect.

“She’s tried to juggle motherhood with being the very high-profile leader of the opposition in Scotland and it’s taken its toll.

“All of this has been made more difficult with the current political climate, where she’s found herself at increasing odds with the new leadership in London. The events unfolding at Westminster are not helped.”

A Scottish Conservative source added: “Ruth will make her position clear in due course. There will be no further comment this evening.”

Davidson, 40, has been leader of the Scottish Conservatives since November 2011, when she beat fellow MSP Murdo Fraser in the party’s leadership contest.

She was widely credited with turning around the party in Scotland and was previously tipped as a future UK Tory leader – but ruled out the move last year, shortly before she gave birth to son Finn in October.

READ MORE: Who will replace Ruth Davidson as Scottish Tory leader?

Another Tory source said: “There are two reasons she has been considering going – family and Boris.”

The insider went on to say Davidson had been under pressure following Johnson succeeding Theresa May as Prime Minister.

“And Ruth is in a real hole with Boris – she can’t defend him, it’s toxic and goes against so much of what she’s fought for.”

Another source said Davidson’s refusal to back Johnson – who she famously suggested was lying during the EU referendum campaign – had angered some senior Tories down south. The insider told The Sun: “One figure at Westminster told me that it was about time ‘Ruth wound her neck in’.”

The bombshell revelation that Davidson is poised to quit will send shockwaves through the party, after she was hailed as the saviour of the Scottish Tories.

At the 2016 Holyrood election, the Scottish Tories doubled their MSP seats to 31, replacing Labour as the main opposition to the SNP.

And at the 2017 General Election, Tory MPs in Scotland rose from one to 13. Their vote share was 28.6% – the best performance since 1983.

A source said Davidson’s refusal to back Johnson during the EU referendum had angered some senior Tories down south. She also backed Johnson’s rival Jeremy Hunt in this summer leadership race in the final run off after previously supporting Sajid Javid and Michael Gove.

After Johnson won, she gave his appointment a lukewarm response, saying she would “judge his premiership by his actions in office”.

She added: “He wasn’t my choice for leader, I didn’t vote for him. However, I will judge his premiership by his actions in office, as will everybody across the country.”