Kevin Rudd has challenged Tony Abbott to allow his party members a free vote on gay marriage but it’s unlikely the opposition leader will change his personal views anytime soon.

The prime minister has announced that if re-elected, federal Labor will within 100 days introduce a bill to parliament to legalise same-sex marriage.

He’s the first Australian prime minister to go into an election promising to support marriage equality.

Rudd, who only reversed his opposition to gay marriage in May, says he’ll allow Labor MPs a conscience vote on the fast-tracked legislation.

“I just urge Mr Abbott to do the same,” he told Nova FM Radio on Monday. “I think it’s time we resolved this matter for all Australians.”

Rudd said the opposition leader had not given his colleagues the chance to vote freely, but it was important such legislation received bipartisan support.

Abbott said he knew the issue was “passionately important” to many Australians, including his openly-gay sister Christine Forster.

But it wasn’t the only important issue, and the coalition would be prioritising “bread and butter issues” like cost of living pressures, job security and infrastructure.

If the issue of gay marriage resurfaced in a future parliament, then it would be up to the coalition party room to decide what policy position to take.

But Abbott said he would be upfront in saying he supported the current definition of marriage as between a man and a woman.

“While my sister Chris has argued with me until she’s blue in the face, and I expect she’ll continue to argue with me on this, I support the existing position,” he told reporters in Melbourne on Monday.

“I pride myself on being consistent and I intend to be consistent.”

Rudd told the popular women’s website Mamamia his daughter Jessica and her “stream of gay friends” helped change his views on gay marriage.