Scotland’s prosecutors could detonate a “political grenade” that derails the SNP’s general election campaign, a nationalist MP has warned them after they confirmed Nicola Sturgeon remains under investigation.

Angus MacNeil urged the Crown Office to provide “clarity” on whether they will “hold off” until after the election on bringing any further charges over the investigation into the SNP’s finances.

The Western Isles MP said any action over Operation Branchform before July 4 had “huge potential to change the narrative of this campaign”.

Although he was expelled from the SNP last year, Mr MacNeil said he was concerned for his former colleagues that their campaigns “could get blown off course if any more charges – or indeed any prosecutions – are brought during the election period”.

He said he was doing SNP MPs “a favour” by writing to the Crown Office as they could not be seen to be trying to influence prosecutors by asking for the information.

His intervention came after Police Scotland announced last Friday, on the second day of campaigning, that a report had been handed to the Crown Office in relation to Peter Murrell.

Mr Murrell, who is Ms Sturgeon’s husband and the SNP’s former chief executive, has been charged in connection with embezzling funds from the party.

The Crown Office also said that investigations into Ms Sturgeon and Colin Beattie, the SNP’s former treasurer, “remain ongoing”.

In a statement, it said that any decisions on what happens next “are not influenced by political events”, suggesting that they would not be specially postponed until after the election campaign.

Angus MacNeil is right, if Nicola Sturgeon is charged during the general election campaign then it will truly bugger up the SNP, as we can see with the latest polling there is a 15.5% SNP to Labour swing which I suspect will get wider if charges are brought against the First Minister.

As Alex Salmond can attest being charged brings no automaticity of being guilty but the court of public opinion doesn’t always believe in innocence until proven guilty, and as the late Lord MacAlpine far too many assume no smoke without fire.

So when betting on Scottish seats and spreads bear in mind there is a potential grenade waiting to be dropped which could bugger up your betting portfolio. Because of Scottish sub-judice rules (which differ from England & Wales) it really limits what could be said in the event of charges which could also cause problems for those charged on a personal level.