THE SNP’s former deputy Westminster leader has intervened in the growing row over claims of a candidate ‘stitch-up’ for next year’s Holyrood election.

Aberdeen North MP Kirsty Blackman warned the party hierarchy against changing the selection process to make it harder for MPs to run for Holyrood.

She said forcing MPs to quit Westminster to stand would also put their staff out of a job.

The plans, due to be debated by the the SNP’s ruling National Executive Committee (NEC) tonight, are seen as an attempt to block MP Joanna Cherry QC.

Ms Cherry, who is close to Alex Salmond, is vying for the SNP candidacy in Edinburgh Central with Angus Robertson, who is close to Nicola Sturgeon.

The selection contest is seen as a proxy battle between factions in the SNP, with Mr Salmond’s side more aggressive on independence, and Ms Sturgeon’s more cautious.

Mr Salmond’s bitter rift with his successor has added an extra dimension to the fight.

Ms Blackman quit as SNP deputy leader at Westminster earlier this month after three years in the role, and is now rumoured to be looking at a move to Holyrood.

The proposed rule changes would block MPs from also becoming MSPs, despite Mr Salmond spending seven of his 11 years at Holyrood with such a ‘dual mandate’.

The NEC will consider forcing MPs to resign their seats if they are selected for Holyrood, creating a by-election to be held on the same day as the Scottish election. 

The plan was put before the NEC last month, but it failed to discuss it because the meeting overran.

Papers for tonight’s meeting suggest raising the bar even higher for MPs by also making them find £10,000 to help pay for the by-election caused by their resignation.

For selected MPs there would be an "added commitment to secure at least £10,000 worth of funding for the subsequent by-election, so that branches in constituencies do not have to fund two election campaigns at once".

READ MORE: SNP architect of independence 'Plan B' sets eyes on Holyrood

In a series of Tweets, Ms Blackman said: “I don’t normally comment publicly on internal party stuff. 

“If a sitting MP decides to stand as an MSP I do understand that there are significant funding issues because that individual is causing a by-election.

“There are also local organisational issues with running one campaign immediately after another. My big concern about asking an MP to stand down much in advance of a Holyrood election is that this will have knock on implications for their staff.

“Asking SNP MPs to do this effectively means that only MPs who are happy to see their staff jobless will be able to stand for Holyrood. 

“This is because their MP staff would no longer have a job either for the interim period or if the MP doesn’t get elected as an MSP.

“I hope the NEC consider this when taking any decision about MPs standing for Holyrood selection. /end (I won’t be making further comment).”

Stand-alone byelections can be extremely expensive for a party to contest.

The SNP spent £99,000 out of a legal limit of £100,000 fighting last year’s Holyrood byelection in Shetland only to lose.

However a byelection fought on the same day as a national election is likely to be much cheaper.

Sourcing £10,000 is unlikely to be a deterrent to Ms Cherry, who had a well-paid legal career before entering politics and also has a generous donor base which gave her £21,000 for her general election fight last December. 

Her high-profile means she should be able to crowdfund another £10,000 relatively easily.

READ MORE: Curtice says SNP splits now ‘biggest risk’ to party’s dream of independence

Writing in the National today, Ms Cherry continued her coded criticism of Mr Robertson, who launched his selection campaign last Sunday by talking up his Remain credentials.

He said: "At present Ruth Davidson holds [Edinburgh Central] for the Tories with a tiny 610-vote majority and I believe that I can win here with the support of SNP members and voters of all parties who don't want to see the area represented by a pro-Brexit MSP." 

He also took a potshot at Ms Cherry by saying he would “support First Minister Nicola Sturgeon”, a reference to his rival’s warmer relations with Mr Salmond.

In her column, Ms Cherry said Brexit was yesterday’s fight and the SNP had lost it - the current battleground was independence.

She pointed out Brexit would be a hard reality once the transition phase lapses at the end of the year, months before the Holyrood election.

She wrote: “It is important that we don’t expend energy fighting last year’s battles. Trying to ‘Stop Brexit’ was the right thing for the SNP to do [at the general election]. 

“It reflected the views of the majority of Scottish voters. It was in the interests of our economy and society to keep Scotland and the UK in the EU. 

“But we lost the battle and Brexit is now an irreversible reality. 

“The SNP will not win future elections merely by fielding candidates who are anti-Brexit. “Brexit is a done deal and the question now is what are we going to do about it? 

“What are we going to do about the democratic deficit that has seen Scotland taken out of the EU against our will and will now see the powers of our parliament and possibly our courts attacked and curtailed? 

“Politicians with the answer to those questions are what is required.”