A French mayor known for his stance against marriage equality says he made an exception for his son.

Raymond Bardet, mayor of Haute Savoie village of Ville-la-Grand, said he put aside his opposition to marry his gay son but promised it wouldn't happen again.

“It seemed perfectly normal for me to carry out the marriage even though I still don't agree with gay marriage,” Bardet told daily Le Dauphine Libere.

“When my son asked me if I'd do it, I immediately told him 'yes,' because I did the same for his sister and because we get on well. I didn't want to give the wrong impression of relations with my family,” he said.

Bardet, 72, strongly opposed last year's passage of a law allowing gay couples to marry, organizing a protest which included a mock marriage between 2 male members of his staff.

“It's normal I made an exception, but it won't happen again. … I have certain opinions and I hold them firmly. At 72 years I'm not going to change,” Bardet said.