A slip of the tongue by Australian Foreign Minister Kevin Rudd fueled more speculation that the former prime minister could be interested in his old job amid calls from the opposition for incumbent Prime Minister Julia Gillard to resign.

Mr Rudd attributes the error to jet lag when his arrived on Tuesday morning at New South Wales.

"I'm a very happy little vegemite being Prime Minister... being Foreign Minister of Australia," ABC Central West quotes Mr Rudd.

Quick to correct his gaffe which could have major political implications, Mr Rudd added, "You've caught me getting off the plane, jet lag."

The minor slip came at a time when reports circulate that some Labor party members are pushing Mr Rudd to regain the party leadership and Ms Gillard's popularity rating is at an all-time low due to the offshore processing issue.

Last week, opposition leader Tony Abbott challenged the prime minister to resign because of her alleged failure to protect Australia's border.

To douse speculations that he wants to return to his former post, Mr Rudd insisted he "fully supported the prime minister" but did not use Ms Gillard's name.

Latest survey indicates that Ms Gillard is fast losing her support, even among women voters. In the last election she was named by 52 per cent of female voters as their preferred prime minister against Mr Abbott who got 33 per cent.

Among female poll respondents who were asked who would make a better prime minister, 39 per cent pointed to Ms Gillard, while 37 per cent preferred Mr Abbott.

Voters said that if an election were held now, many would still vote for Labor, but hinted they want another party leader to become Australia's next prime minister.

"This Labor government has failed terribly on the refugees, they should be treated humanely.... It seems like the government's in a position where they're just grasping for anything they can get hold of. I like Julia Gillard but I don't think Kevin Rudd was doing such a bad job," The Australian quoted Sydney resident and Labor supporter Annabel Horne.