Tony Abbott believes Barnaby Joyce is doing a "very good job" in finance although his Liberal colleague Ian Macdonald thinks his talents could be better used elsewhere.
The surprise resignation of Nick Minchin from the shadow ministry on Wednesday has fuelled speculation about whether the opposition leader might move Senator Joyce from the portfolio.
Since taking up the job last year, Labor has attacked the Queensland Nationals senator over his competency for the role following a number of gaffes on financial issues.
There has been speculation communications spokesman Tony Smith, former adviser to former Howard government treasurer Peter Costello, might be keen for the job.
But a source close to Mr Smith denied he was seeking the role.
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A number of Liberal MPs suggest Senator Joyce won't be going anywhere.
That was the indication Mr Abbott gave on Thursday when he once again backed his shadow minister.
"Barnaby is not your white bread politician, there's no doubt about that," he told ABC local radio.
"Precisely because he's an unorthodox politician he has been very effective at putting Labor's debt and deficit before the public.
"I think he's done a very good job in that portfolio."
Senator Macdonald has a different take on the situation.
"I just wonder whether his obvious talents and his special communication skills could be put to a better use," he told ABC Radio.
Senator Macdonald and Senator Joyce are understood to have been on opposite sides of the divisive climate change debate last year.
There are tensions too between Liberals and The Nationals in Queensland where they work together under the LNP umbrella.
Mr Abbott has a number of options available to him to replace Senator Minchin.
Andrew Robb is currently without portfolio within shadow cabinet, he could invite former Liberal leader Malcolm Turnbull on to his frontbench or promote a talented junior minister.
Mr Turnbull wasn't commenting on the issue.
One person who has staked a claim to Senator Minchin's role as opposition Senate leader - which is decided by senators - is Tasmanian Liberal Eric Abetz, who announced his candidature on Thursday.
Senator Abetz, from the right, is expected to be unopposed but sources say that is conditional on George Brandis, a moderate, being unopposed as deputy opposition Senate leader.
