Nicola Sturgeon's husband has quit as chief executive of the SNP after he was warned that he faced being ousted if he did not stand down. 

Peter Murrell, who has led the SNP for almost 25 years, said on Saturday morning that he would step down "with immediate effect".

He said that he took responsibility for misleading the public and the media about the size of the SNP's membership, who are voting to elect the successor to his wife as party leader.

Pressure on him had mounted after the SNP's press chief at Holyrood, Murray Foote, quit on Friday night, claiming he had been misled into issuing incorrect figures.

In a statement, Mr Murrell said: "Responsibility for the SNP’s responses to media queries about our membership number lies with me as Chief Executive. 

"While there was no intent to mislead, I accept that this has been the outcome. I have therefore decided to confirm my intention to step down as Chief Executive with immediate effect."

He added: “I had not planned to confirm this decision until after the leadership election. However as my future has become a distraction from the campaign I have concluded that I should stand down now, so the party can focus fully on issues about Scotland’s future. The election contest is being run by the National Secretary and I have had no role in it at any point."