Jeremy Clarkson has warned that redefining marriage is a distraction from more important issues.
Mr Clarkson drew a parallel to Tony Blair and fox hunting – a controversial issue which proved to be far more controversial than Mr Blair had imagined.
Writing in his weekly Sun newspaper column, Mr Clarkson criticised David Cameron for talking about his support for same-sex marriage in the middle of other problems.
Mr Clarkson wrote: “This week, Britain fell deeper into recession and small boys were getting on aeroplanes with no tickets or paperwork of any kind.
“So out popped Mr Cameron to tell us, once again, about why he supports gay marriage.
“Same-sex marriage is to the Tories what the hunting debate was to Tony Blair.
“When everything is chaotic, bring it up and everyone suddenly forgets about everything else.”
Last week Mr Cameron repeated his commitment to redefine marriage by 2015, regardless of what the public or his own backbenchers think about it.
The Prime Minister, who was speaking to gay activists, also lashed out at churches for “locking out” gays by supporting marriage between one man and one woman.
He praised Tony Blair for introducing civil partnerships, then said: “I just want to say I am absolutely determined that this Coalition government will follow in that tradition by legislating for gay marriage in this Parliament.”
The Prime Minister also said that the Church is on the wrong side of the argument and should not “be locking out people who are gay, or are bisexual or are transgender”.
But The Christian Institute said Mr Cameron was displaying his own intolerance and prejudice against Christians who oppose gay marriage.
In March BBC TV presenter Andrew Marr also compared the rows over same-sex marriage and fox hunting, saying: “I’m beginning to wonder if this could turn out to be David Cameron’s version of the hunting ban, which you may remember dogged Tony Blair to everyone’s surprise, for so long.”