The ninth Earl of Arran, one of the few remaining hereditary peers in the Lords and the owner of a 5,000-acre estate, says he fears for the future of a “decadent” Britain if the Marriage (Same Sex Couples) Bill is signed into law.

Peers will resume debate on the bill at 3pm this afternoon with a vote expected at around 7pm.

Confirming that he will vote against the bill to the North Devon Journal, Lord Arran said: “I’m one of those, maybe old fashioned, people who think the whole point of marriage is to produce children.

“While two people can still be happily married without children I don’t see the point,” he said.

Lord Arran’s father voted in 1967 to decriminalise homosexuality, but Lord Arran believes his father, like he, would not support the government’s legislation.

“He was a very brave man,” said Lord Arran, “and he bought about this decriminalisation in 1967.

“But at the time he said he very much hoped as a result there wouldn’t be any ‘flaunting’ of homosexuality. I feel like this bill could be that.”

“Is the government going to insist 10% of MPs must be gay?” Lord Arran pondered.

“I’m joking of course, but where is it going to stop?”

He added: “The Roman empire fell for three reasons. There was the worship of sporting heroes, widespread corruption and the decadence and flaunting of homosexuality. I fear that in this country we aren’t too far from being decadent.”

Lord Arran and his wife, the Countess of Arran, own more than 45 properties on their 5,000-acre estate in north Devon.

Speaking during yesterday’s second reading debate of the bill, Lord Hylton, a crossbench hereditary peer who joined the Upper House in 1968, said gay people had stolen the word ‘gay’ from its original “delightful meaning”.