EWAN Morrison, the award-winning writer and director, has explained how he switched from being a Yes to a No supporter in a devastating blog that describes the independence campaign as self-censoring, conformist and cult-like.

The author of Close Your Eyes and Swung, a one-time SNP member, said he joined the Yes campaign to take part in the debate over Scotland's future.

But he abandoned the movement after becoming frustrated at fellow campaigners' refusal to confront serious economic questions and their determination to close down debate.

He said support for Yes has become "a form of faith" for members of the pro-independence movement, who project a range of conflicting and contradictory visions of Scotland onto their desire to leave the UK.

In a lengthy blog published yesterday, he said dissenters were silenced by believers.

He wrote: "Questioning even triggered a self-policing process - The Yes Thought Police - rather like the Calvinist one in which doubters started to hate themselves and became ­fearful of showing signs of their inner torment.

"I have witnessed some of the greatest minds within Scotland go through this process, one week they are vocally discussing complex issues like global ­capitalism and the next they're posting 'selfies' of teenagers waving flags and photos of cute puppy dogs carrying Yes signs in their mouths.

"The conformist dumbing down has been acute and noted by those outside Scotland who wondered where all the intellectuals went." Recalling his time in the Socialist Workers Party back in the 1980s, he added: "The Yes movement started to remind me of the Trotskyists - another movement who believed they were political but were really no more than a recruitment machine."

Without debate, he said Yes has become "an empty word and an empty political process".

Explaining his decision to vote No in tomorrow's referendum, he said the independence movement had failed to acknowledge the "exhausting and frustrating" daily fights and compromises of politics.

He said: "I left the Yes camp and joined the No camp not because I like the UK or think the status quo works well as it is.

"No. I think things are as complicated and compromised as they always are and that we live in trying times.

"The Yes camp understand that and so have created an illusion of a free space in which everything you've ever wanted can come to pass - overnight.

"How can it? There are exactly the same political conflicts within the factions of Yes as there are within the UK."