Select committees are cross-party groups of MPs tasked with scrutinising the actions of government and its ministers; the transport committee has oversight for aviation, cruise and rail, among other sectors.
Conservative MP Merriman, who has been a prominent supporter of the travel industry throughout the Covid pandemic, will relinquish his chairmanship of the committee to focus on his new role at the DfT.
Select committee chairs are allocated according to party, with transport falling to the Conservatives meaning only a Conservative MP can stand for the role, although all MPs can vote.