OTTAWA — Three federal byelections will end today with a promise of more to come, now that Prime Minister Mark Carney has to schedule another six of them. Liberal MP Steven Guilbeault officially resigned his Montreal seat of Laurier—Sainte-Marie on Friday, according to the House of Commons website. Guilbeault has said he’s leaving government on a matter of principal because the party’s direction on energy and the environment changed under Carney’s leadership. Conservative MP Cathay Wagantall is also expected to officially resign today, something she announced in June. This year has seen a revolving door of MPs leaving the Commons as many elected officials looked for opportunities elsewhere. The prime minister must call a byelection within 11 to 180 days after a seat becomes vacant.