“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.

“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.”