Will the Nationals try to retake the trade portfolio?

Finance Minister Mathias Cormann is retiring at the end of October, with Trade Minister Simon Birmingham picking up his portfolio.

However, a cabinet reshuffle is expect at the end of the year, and questions have been asked of the Nationals, querying if the party will attempt to stake a claim on the trade portfolio due to its importance to the ag sector and regional economies.

Since the mid-1950s, the trade portfolio has always held by a Nationals MP in Coalition governments, with former party leaders John McEwen, Doug Anthony, Tim Fischer, Mark Vaile and Warren Truss all holding the position of Trade Minister.

That tradition was broken in 2013, when Liberal Andrew Robb was appoint the role, and it has since been held by Liberals.

Agriculture Minister David Littleproud, who spent much of the post-budget period spruiking the $328 million the government has committed to supporting agricultural exports, was coy when asked about the party's ambitions.

"I'm sure those discussions will take place later in the year - there will not be a reshuffle until the end of the year," Mr Littleproud said.

"For now Simon [Birmingham] will continue on in that role. He's doing an exemplary job in terms of what he's been able to achieve.

"There will be continued discussions between the Coalition partners when that reshuffle happens."

Labor agricultural spokesperson Joel Fitzgibbon didn't miss an opportunity to take a jab at the Nationals for rolling over on their traditionally-held portfolio.

"The Nationals always owned the trade portfolio forever until that changed with Andrew Rob," Mr Fitzgibbon said.

"Black Jack McEwen, Tim Fischer and John Anderson would have never let the Libs push them around like that.

"When are they going to start muscling up to the Libs? They've put them in the corner and don't expect them to have any part in the decision making process."