Jim Molan's political comeback complete

Liberal senator Jim Molan has officially returned to federal parliament, with the former major general sworn in to the upper house.

The NSW senator lost his seat after being bumped down the Liberal ticket at the May election, but returned on Monday to replace Arthur Sinodinos, who left to become Australia's ambassador to the United States.

Senator Molan, who has committed to staying on only until the next election, was sworn in during a ceremony in Canberra.