An Australian political advisor has called the Irish “people who can’t grow potatoes” and said “they’ve got a mutant lawn weed as their national symbol” in a debate on same-sex marriage.

Grahame Morris, former chief of staff for Liberal Party politician John Howard when he was prime minister, said Australia should not follow Ireland’s example in having a same-sex marriage referendum during a TV debate.

The opposition leader in Australia, Labor’s Bill Shorten, had proposed a bill on Monday to recognise same-sex marriages and overturn the national ban.

Mr Morris said the “trigger” for the bill was the Yes vote for same-sex marriage in Ireland.

Video: Debate on Ireland starts 7:46

“Now I love the Irish, the parliament is full of Irish men but these are people who can’t grow potatoes, they’ve got a mutant lawn weed as their national symbol and they can’t verbalise the difference between tree and the number three. But, and then all of a sudden, Australia has to follow suit,” he said on Sky News.

Mr Morris said Australians were not ready for the referendum and it would be a divisive issue.

“I don’t think people are ready. You run around Queensland, the Bush, and most of Western Australia and you can see people aren’t ready.

“This vote is going to be divisive and I don’t think most of the parties in parliament are ready to change.

“It isn’t a life and death decision.

“I have a feeling this could end up like that stupid referendum on a republic where the electorate wasn’t ready... and you’ve got to put it off for another ten years.”

Support for legalising same-sex marriage there was at 72 per cent, according to a survey of 1,000 people conducted over the telephone in Australia a year ago by polling agency Crosby-Textor.