Australian government back-bencher Dennis Jensen, has asked why people can’t marry their biological relatives if gays are allowed to marry.

Jensen asked why he shouldn’t be able to marry his immediate blood relatives if same sex marriage is legalised.

In Parliament on Monday he said: “I love my siblings, I love my children, I love my parents, but does that mean that I should marry them?”

He also asked why incestuous brothers and sisters should not be allowed to marry if same-sex couples can, as long as they agreed not to produce any children.

Jensen added: “Apart from the yuck factor, that is our natural genetic pre-disposition of these sorts of relationships due to our innate knowledge of the genetic problems they’d cause, why not allow incestuous marriage if one or both parties agree to be sterilised?”

Accusing supporters of same-sex marriage, he said they were making a fundamental error if they believed that marriage was only about love.

“Why not polygamy, polyandry?”

“How about the love of, say, two sisters who have lived together for most of their lives? Should that be called marriage?” He said.

Jensen also compared same-sex marriage to Communism, saying: “Once seen as inevitable, now consigned to the dustbin of history.”

Despite all this however, he said that he is open to non-heterosexual people being able to formalise their relationship through other kinds of union, as long as it was not marriage.