Barnaby Joyce has backed conservative calls to delay a vote to decriminalise abortion in NSW, invoking his new baby son, Tom.

The former deputy prime minister rose in federal parliament shortly before question time on Thursday to weigh in on the NSW debate.

“On the first of June, Vikki’s and my son Tom took his first breath,” Mr Joyce said.

“This was not the start of his life. The reality is he was part of this world for some time and was merely passing from one room to another.”

Conservatives are pushing for the NSW legislation to be delayed and sent to a committee after the state government surprised many by bringing on a vote this week.

Mr Joyce backed that delay and said the rights of children such as his son could not be removed by a state parliament.

“Inside the womb, Tom kicked, punched, grabbed his umbilical cord, felt pain, slept and dreamed – to say he didn’t have the rights of other human life is to say he must be sub-human,” Mr Joyce said.

“I don’t believe that any person, any doctor, any parliament has the power today to declassify another person as less than human and by so doing removing their most fundamental right to be alive.

“In the NSW parliament they are debating whether Tom had no classification or human rights.”

Independent NSW MP Alex Greenwich has introduced a historic bill to decriminalise abortion in the state. It is co-sponsored by MPs all sides of politics.

Supporters of the change say that conservatives are wrong to suggest the laws would extend abortion rights or allow women to have late-term abortions at more advanced stage of pregnancies than they already do.

There are no current time limits on when a woman can have an abortion in NSW. In practice, however, the number of women having later-term abortions is small and makes up only about 1 per cent of all terminations.

“The law surrounding terminations is no longer fit for purpose and need to be modernised,” Mr Greenwich told NSW Parliament.

“The threat of prosecution of women and health care professionals is real. As recently as August 2017, a Blacktown mother of five was prosecuted for self-administering a drug to cause a miscarriage.”

Mr Greenwich said the proposed laws would actually involve more doctors to review cases for later-term abortion.

He dedicated his speech to his late grandmother Jacqui, who instilled in him the right of women to choose when he was a child.

“When I was 10, I clearly remember Jacqui – she didn’t like being called grandma – sharing with me a letter she had written to then US president George HW Bush, outraged at his anti-abortion stance,” Mr Greenwich said.

“This was my first experience with any form of political activism and Jacqui instilled in me the importance of women, not politicians, having control of their own bodies.”