With several byelections already pending, Prime Minister Mark Carney is expected to call another after Liberal MP Shaun Chen announces his resignation, according to a Liberal source. Chen, who has represented the riding of Scarborough North since 2015, will be stepping down later this month due to health concerns following a car accident he was involved in last fall, the source told CTV News. The resignation will be the latest in a slew of MPs from all political parties that have announced they are stepping down from their federal posts this year. Three byelections are coming up on Aug. 31 for the ridings of Beaches-East York in Ontario, Chicoutimi-Le Fjord in Quebec and North Vancouver-Capilano in British Columbia. They are being held to replace former Liberal cabinet ministers Jonathan Wilkinson and Nate Erskine-Smith and Conservative MP Richard Martel who is headed to the Senate. Other byelections have yet to be called. Last week, Conservative MP Larry Brock, who represents the riding of Brantford-Brant South, announced he is leaving the House of Commons on Sept. 18, to take a position at the Crown attorney’s office in Brantford, Ont. Conservative Saskatchewan MP Cathay Wagantall, meanwhile, announced she is stepping down at the end of August, as will former Liberal cabinet minister Steven Guilbeault. Current Independent and former NDP MP Alexandre Boulerice is expected to resign by the end of summer after he declared he is running for the Quebec solidaire in the Quebec election this fall, while Bloc Québécois MP Simon-Pierre Savard-Tremblay also resigned his seat in June to run for the Parti Québécois. The prime minister must call a byelection between 11 and 180 days after a seat becomes vacant. With the current vacancies, Carney’s Liberals hold a majority with 172 seats – the exact number required to form a majority government. The House of Commons is set to resume on Sept. 21. With files from CTV News’ chief political correspondent Vassy Kapelos This is a breaking news story. More details to come…