CANBERRA - John Howard could become the first sitting prime minister to lose his seat for almost 80 years according to a new poll yesterday.

A Galaxy Poll conducted for the Sunday Telegraph points to Howard facing a humiliating defeat in his own seat of Bennelong at the hands of glamour Labor candidate Maxine McKew.

The poll shows Liberal voters continuing to desert the Prime Minister's cause in droves.

If he was beaten by former TV journalist McKew, Howard would be the first sitting prime minister to lose his seat since Stanley Melbourne Bruce in 1929.

The Sunday Telegraph/SBS Insight Galaxy Poll was conducted on the evenings of August 8 and 9, based on a sample of 800 voters. It found 47 per cent of those surveyed intended to give their first preference vote to McKew while 44 per cent intended to vote for Howard.

Support for McKew is now 19 points higher than the vote achieved by the ALP candidate at the last federal election.

The newspaper said the fact Howard had been unable to claw back McKew's lead - despite Budget tax cuts and family benefits coming on stream and initiatives such as the intervention in indigenous child abuse in the Northern Territory - would reinforce perceptions that voters were no longer listening to the Prime Minister.

Both Labor and the coalition were playing down the poll yesterday.

While Howard, Labor leader Kevin Rudd and McKew made no public comments on the Bennelong poll result, Opposition frontbencher Bob McMullan, a former Labor national secretary and Cabinet minister, said McKew was an excellent candidate but that it would be very hard for her to defeat Howard.

"Maxine's a terrific candidate and as people meet her they warm to her and like her and I think she will do very well," he told ABC TV. "But it's far too early to say that that means she's going to win."

McMullan said many Australians were yet to make a final decision on how they would vote at the election later this year.

"We're very near the end of this three-year term and people are open to the idea of change but I think their voting intention isn't set in concrete at all. It's quite fluid," he said.

Foreign Minister Alexander Downer also believed voter support for the major parties was still fluid but said he was confident Howard would lead the coalition to victory.

"There's always controversy about the record of the incumbent and so on - it happens everywhere," he told the Nine Network.

"But when it comes to voting, in the end I suspect that people are more likely to vote for a leader with a record, with wisdom, with substance, than somebody who's just ... a manufactured product of a public relations company with no plan for the future."

However, the poll suggested that after last week's rate rise, voters have solidified their support for McKew, reflecting national polls that show Howard has been unable to substantially cut Rudd's big lead.

The newspaper said Howard faced a 7 per cent swing in Bennelong, putting McKew in a commanding position with 53 per cent of the vote after distribution of preferences. The seat only needs a 4 per cent two-party preferred swing to change hands.

The newspaper said it understood the Galaxy poll was in line with internal ALP research in Bennelong. Labor needs a national swing of 5 per cent to take power.

The newspaper said Labor saw Environment Minister Malcolm Turnbull's "now marginal seat" of Wentworth and Bennelong as the last seats the party needed to win to take office.

The polls also suggest things have turned sour for Howard in Western Australia. A Westpoll published this weekend shows a shock swing of 8 per cent to Labor, delivering the Opposition 54 per cent of the two-party preferred vote. That would give Labor three more seats in WA.

- AAP