A gay SNP politician has hit out at colleagues on the issue of gay marriage, calling them bigots.

Alyn Smith, an MEP who was elected in 2004, attacked colleagues who signed a motion on gay marriage, calling them “small” and “mean”.

SNP MSP John Mason tabled a motion last month which says that no one should be forced to approve or be “involved with” gay marriages. Three other SNP politicians – Bill Walker, Richard Lyle and Dave Thompson – are supporting it.

Mr Mason has been criticised by a number of MPs from other parties.

Mr Smith said: “What is in the small, mean, angry heads of bigots is a matter for them. I have never asked for their approval, but I demand equality.

“Sadly, the motion before our nation’s parliament lacks any idea of respect at all. The plea that nobody should be forced to even approve of same sex relationships, never mind marriage, is just plain odd.”

Mr Mason said he was trying to stop the debate from “just flowing in the one direction”.

He added: “I’m perfectly relaxed about gay marriage but the fear amongst some of the churches is that if they’re allowed to carry out same-sex marriage some will and some won’t. The next step will be that someone goes to a church that doesn’t want to and it will get taken to court.”

Last week, Pete Wishart, the SNP MSP for Perth and North Perthshire, wrote on Twitter: “John Mason’s nasty little anti-gay marriage motion is just wrong, and really disappointed that other colleagues have signed it.”

Deputy Scottish Labour leader Johann Lamont said Mr Mason’s views were “bizarre”, while Green MSP Patrick Harvie, who is gay, accused him of being stuck in the “dark ages”.