Family Court Chief Justice Diana Bryant, who has presided over many hundreds of disputes involving broken families in her 17-year career as a family law judge, said what children needed most was to be surrounded by ­stable, functional relationships. “What you want for children is a stable, loving and ­caring relationship in which they are brought up,” she told The Australian. “It ­really doesn’t matter who their parents are as long as they have all of those aspects, and if they do, there is absolutely no reason why there should be any discrimination in my view.

“What you don’t want children to have is to be living in a confected, dysfunctional relationship — whether it is two parents of the same sex, or two heterosexual people.”

In a rare intervention in a key debate, Chief Justice Bryant said same-sex marriage would have no effect on the way the Family Law Act applied to children. This is ­because the legislation applies in exactly the same way to married and de facto couples and their children, regardless of whether they are in a heterosexual or same-sex relationship.

“The Act applies equally to children of same-sex couples as it does to children of heterosexual couples,” Chief Justice Bryant said. “Apart from divorce itself, if the Marriage Act was changed it is not going to make any difference to the way in which the Act ­applies.”

Her confirmation that changes to the Marriage Act would have no effect on the nation’s family laws follows a dramatic intervention in the same-sex marriage debate from former prime minister John ­Howard, who took out a full-page newspaper advertisement in The Weekend Australian urging the government to “spell out” the steps it would “take to protect ­parental rights, freedom of speech and religious freedom”.

Mr Howard argued it was ­“disingenuous to assert that a change of this magnitude to a ­fundamental social institution does not have consequences”.

However, the Rudd government already had delivered many of the practical changes that otherwise would have been associated with same-sex marriage — providing equality for same-sex couples and their children in areas such as social security, employment, taxation, health, aged care and superannuation.

Labor equality spokeswoman Terri Butler said it was “unfortunate” Mr Howard had chosen to use his standing as a former PM to advocate for the No campaign.

“It was the ­Howard government which changed the ­Marriage Act a long time ago to explicitly say the marriage is ­between a man and a woman,” Ms Butler said. “It is a bit rich coming from someone who did change the marriage law without any need for a national opinion poll or a ­plebiscite or anything like that.”

Today the Australian Bureau of ­Statistics will release the turnout rate so far for the marriage survey.