Indigenous Affairs Minister Nigel Scullion is facing speculation he could be dumped from cabinet as the emboldened Nationals meet to discuss a push for more frontbench positions in the Turnbull government.

Nationals MPs will meet at Parliament House on Tuesday afternoon amid reports suggesting Senator Scullion may step down from cabinet or be asked to go by leader Barnaby Joyce.

The party expects to pick up at least one extra frontbench position after winning an additional seat at the July 2 election, growing the proportion of the party's representation inside the Coalition.