Mr Abbott, who was reluctant to endorse Senator Joyce publicly yesterday, also backed away from Senator Joyce's call to make cuts to the public service, but did not discount the idea altogether.

At the same time, the government stepped up its assault on the Nationals senator as it sought to portray him as a liability for the Coalition's economic credentials.

In Parliament, the Finance Minister, Lindsay Tanner, read a litany of blunders or untrue claims Senator Joyce had made in recent days and then described him as ''a freak show''.

''The bearded lady of Australian politics, he's taken charge of economic policy. If he ever gets control of the public finances of this nation, God help Australia.''

Senator Joyce stirred controversy on Wednesday when he mused about ways the Coalition would make budget savings. He flagged cutting public servants and made an argument for paring back foreign aid.

He singled out $50 million that Australia had given the World Bank for a food program.

That money, the bank says, is used in a number of impoverished nations ''to feed poor children and other vulnerable groups, provide for nutritional supplements to pregnant women, lactating mothers, infants and small children, to meet additional expenses of food imports or to buy seeds for the new season''.

Senator Joyce insisted yesterday that everything was on the table. But Mr Abbott stepped in, reaffirming the bipartisan commitment to increase Australian aid as a percentage of gross national income from 0.34 per to 0.5 per cent by 2015-16. ''The Coalition has no plans to cut the foreign aid budget and the Coalition supports the public service.''