Former Louisiana Speaker Hunt Downer (R) plans to file paperwork Thursday to officially enter the open-seat 3rd district race to succeed Rep. Charlie Melancon (D).

Downer, a retired major general in the National Guard who is expected to have the backing of his party’s establishment in the race, has been widely expected to run in the conservative southern Louisiana district. He enters the GOP primary as the heavy frontrunner against attorney Jeff Landry.

The winner of the GOP contest will face Democratic attorney Ravi Sangisetty in the general election.