Prime Minister Julia Gillard should expect tougher days ahead of the Sept 14 election since a growing number of Australian Labor Party members are pushing former Prime Minister Kevin Rudd to break his promise and challenge Ms Gillard's leadership of the party.

Even the Coalition is preparing for a Rudd challenge to the ALP top post. The Rudd challenge comes at a time that sexism issues are being hurled at Australia's first prime minister over her recent show of her cleavage and the question on the sexual preference of her partner, hairdresser Tim Mathieson.

So far, Mr Rudd has refused to budge from his previous promise no longer to challenge the party's top position, probably burnt from his previous attempt that led to his defeat.

Other ALP members, however, continue to hope for a change with prominent Labor member Peter Beattie saying the perhaps former Prime Minister Bob Hawke could serve as the bridge to settle the leadership battle between Ms Gillard and Mr Rudd.

"You've got to find a new approach and the only way to do that, in my view, is to get Bob Hawke to get both leaders in a room and have a discussion about how to resolve it," Skynews quoted Mr Beattie.

The Labor caucus is scheduled to meet Tuesday, June 18.