Nationals MPs Darren Chester and Keith Pitt will be sworn in to the ministry next week, confirming their return to the Turnbull government frontbench less than three months after being dumped.

New Deputy Prime Minister Michael McCormack opted for minor changes in his first major decision since rising to Nationals leader.

Mr Chester will be made veterans’ affairs minister on Monday, while Keith Pitt will officially become assistant minister to Mr McCormack at the swearing-in ceremony in Canberra.

Deputy speaker of the House of Representatives Mark Coulton was also promoted to the ministry as assistant minister for trade.

Mr Chester, a former cabinet minister, and Mr Pitt were dumped from the frontbench in Barnaby Joyce’s controversial reshuffle late last year.

Senior MPs who were strong supporters of Mr Joyce were spared the axe, with Resources Minister Matt Canavan and Indigenous Affairs Minister Nigel Scullion untouched in the reshuffle.

The news wasn’t as good for two of their junior ministerial colleagues with Damian Drum and Luke Hartsuyker demoted.

Nationals elder statesman Tim Fischer, who was deputy prime minister from 1996 to 1999, praised Mr Chester’s return to the frontbench.

“Darren Chester will be an outstanding veterans’ affairs minister, particularly for the opening of the new Sir John Monash Centre (in Villers-Bretonneux) next month,” Mr Fischer told AAP.

Mr McCormack was elevated to the leadership on Monday after Mr Joyce resigned following a 16-day scandal surrounding his affair with a former staffer who is now pregnant.