The former leader of the Scottish National Party Gordon Wilson has once again criticised the leadership of the SNP for supporting equal marriage.

He is due to tell the party at a fringe event at its conference this week in Perth that plans to legalise same-sex marriage in Scotland are a step towards “state fascism”.

In September, the Scottish Government announced that an equal marriage bill would be voted on by MSPs within the current parliamentary term.

Over the weekend Mr Wilson, who led the SNP from 1979 to 1990, also branded the Scottish Government’s consultation on same-sex marriage as a “fraud” and warned MSPs not to “scorn” the electorate in a free vote on the issue.

According to the Scotsman, Mr Wilson will say in Thursday’s speech:

“If you think we are sliding down a road to state fascism and intolerance, you may not be far wrong. Be warned, those MSPs of all parties on a narrow majority who exercise their ‘free’ vote for same-sex marriage.

“They may find that a free vote has as much validity as a ‘free’ lunch. If they ignore public opinion, a P45 may await. Do not scorn the electorate”.

In response, Tom French, of the LGBT campaign group the Equality Network, said: “The opponents of LGBT equality have sunk to a new low by comparing equal marriage supporters to fascists and Nazis.

“The fascist regimes of the 20th century persecuted, tortured and murdered LGBT people. In contrast, the Scottish Government are promoting equality and religious freedom for all.

“No religious body will be required to conduct same-sex marriages, but those that want to will now have the freedom to do so. This is a fair compromise that is supported by over two-thirds of people in Scotland.”

Last week, gay rights campaigners criticised the former Archbishop of Canterbury Lord Carey for mentioning Nazi Germany during a speech against equal marriage at a Conservative Party Conference fringe event in Birmingham.