Senator Joyce is being targeted remorselessly by the government because of his comments, which it deems irresponsible for the alternative finance minister.

On Tuesday, the government pressed Mr Abbott to sack Senator Joyce after he questioned Australia's capacity to repay its debt. Mr Abbott hit back yesterday, saying Labor attacked Senator Joyce at its peril: ''Every time the government makes nasty personal attacks on my colleague, they actually draw attention to the debt problem they've created''.

But there is growing unrest inside the Liberal camp about Senator Joyce's impact on the party's economic credentials.

Mr Abbott refused to guarantee Senator Joyce would be his spokesman by the time Kevin Rudd called the election. All he would say was that ''this is the team I will take to the election''.

One minister said the government would not back off from Senator Joyce, believing it had no option but to go after him, just as Labor went after Pauline Hanson.

If this made Senator Joyce more popular among his natural constituency, then so be it, the minister conceded.

Several Liberals said although Senator Joyce was good at raising issues, his tendency to make gaffes was proving a liability with the corporate sector and the Liberal heartland.

''No one thinks he's any good but there's no easy way to sack him now,'' said one MP. ''Tony is travelling well but there's a distraction every second day.''

These concerns were shared by Liberals who both liked and disliked Senator Joyce, the MP said.