The SNP were hit with a bombshell just days before their annual party conference, as MP Lisa Cameron defected to the Conservative party.

The representative for East Kilbride, Strathaven and Lesmahagow announced her decision on Thursday morning, hours before her likely deselection.

Here's what you need to know in five minutes.

Who is Lisa Cameron?

Born in Glasgow and raised in East Kilbride, Ms Cameron is a trained psychologist who worked in the NHS before making the move into politics.

She's a trade union representative for Unite, and joined the SNP in the wake of the no vote in the 2014 independence referendum.

She was first elected to the East Kilbride, Strathaven and Lesmahagow seat in 2015 and has served that constituency ever since.

Read More: SNP MP Lisa Cameron defects to the Conservatives hours before likely deselection

Why has she quit?

Ms Cameron has had a difficult relationship with the SNP leadership for some time, she says since she spoke out in support of the harassment victim of fellow SNP MP Patrick Grady.

She told MailOnline: "I do not feel able to continue in what I have experienced as a toxic and bullying SNP Westminster group, which resulted in my requiring counselling for a period of 12 months in Parliament and caused significant deterioration in my health and wellbeing as assessed by my GP including the need for antidepressants.

"I will never regret my actions in standing up for a victim of abuse at the hands of an SNP MP last year, but I have no faith remaining in a party whose leadership supported the perpetrator's interests over that of the victims and who have shown little to no interest in acknowledging or addressing the impact."

It's also worth noting that the move comes on the day she was facing a selection battle to be the candidate for her constituency at the next general election, expected next year.

Her opponent, Grant Costello, has the backing of a number of high-profile SNP members including MSPs Christina McKelvie and Collette Stevenson and former MP Linda Fabiani.

Ms Cameron was accused of "real misogyny" by Ms Fabiani's partner, Duncan McLean, after suggesting the former parliamentarian had only endorsed her opponent because Mr McLean failed to be selected in 2015.

Is this a surprise?

The Herald:

Yes and no.

Ms Cameron had threatened to force a by-election if she was not re-selected, but defecting to the Tories came somewhat out of the blue.

She says Prime Minister Rishi Sunak reached out to her about her allegations of bullying, something she says the SNP failed to do.

Still, it's quite something for her to hit out at the 'division' caused by her former party's independence policy and declare: "I have come to the conclusion that it is more helpful to focus my energies upon constructive policies that benefit everyone across the four nations of the UK, and to move towards healing these divisions for the collective good".

Does she have any other issues with the SNP?

Aside from apparently having a change of heart about the party's raison d'etre, she's had a number of other differences of opinion with leadership in recent years.

She was the only SNP MP to vote against a bill to ban protestors from standing outside abortion clinics in England.

Read More: Cameron claims she's been shunned because of support for Grady victim

Ms Cameron and Peter Grant were the only two SNP MPs to vote against lifting Northern Ireland’s abortion ban in 2018. 

She also personally wrote to Scottish Secretary Alister Jack on the day he blocked the Gender Recognition Reform Bill, passed by the Scottish Parliament, from receiving royal assent saying her constituents wished the UK government to "intervene to prevent this".

What happens now?

Ms Cameron will sit as a Conservative MP until the next general election, which is expected to be next year.

Scottish Conservative leader Douglas Ross welcomed her with a post on social media stating: "It's great to have Lisa Cameron on board. The Scottish Tories will stand up for everyone who has been forgotten by the SNP to get the focus onto Scotland's real priorities."

It's unlikely that she'll retain her seat at the next election though.

East Kilbride, Strathaven and Lesmahagow has been subject to boundary changes, so at the next election the seat will be East Kilbride and Strathaven but it hasn't traditionally been fertile ground for the Tories.

Labour took around 50% of the vote at the 2005 and 2010 elections, with Ms Cameron holding the seat as an SNP MP for the following three.

At the 2019 election the Conservative candidate, Gail McGregor, took just 21.2% of the vote.

With the Tories currently expected to be soundly beaten at the general election, you wouldn't bet on her defeating either her former party or Scottish Labour.