MPs are voting to decide who will be the first chair of the Commons' critical backbench business committee.
Labour's Natascha Engel, the MP for Derbyshire North East, is taking on Conservative Sir Alan Haselhurst, former deputy Speaker, in the two-horse race.
The winner will be tasked with standing up for backbench MPs' interests as control of the Commons' agenda is slowly transferred from the government to MPs.
Under the plans proposed by the reform of the House committee in the last parliament the backbench chair would meet with representatives of the government and the opposition in a House business committee which would "come up with an agenda for the week ahead".
It will largely be up to the backbench business committee to determine how to fulfil its task of organising non-ministerial business, the report noted. It envisaged at least one day a week of parliamentary business being controlled by the committee.
"We feel that this is an essential reform which will have many benefits for members, for parliament as a whole, and for the esteem in which it is held," the Wright committee noted.
"But these gains will not be realised unless individual backbenchers are committed to parliamentary activity and avail themselves of these opportunities, and that will only happen if they think it a more worthwhile use of their time than the many other tasks which make up the life of an elected member."
MPs are voting between 09:00 BST and 11:00 BST this morning.