NDP transport critic Hoang Mai is asking for "transparency" on Transport Canada's handling of General Motors' worldwide recall of 1.6 million compact cars for defective ignition switches.

The recall, which affects compact cars sold in Canada, U.S. and Mexico, concerns a faulty ignition switch. According to GM, a heavy key ring or jarring can cause the ignition switch to shift out of the run position and shut off the engine and electrical power. That could disable, among other things, the front air bags.

"We hope Minister (Lisa) Raitt will appear before the standing committee on transportation, infrastructure and communities to provide clarity on what Transport Canada has known over the past decade regarding this issue," Mai said at a news conference on Tuesday.

Mai's statement comes after Transport Canada disclosed last week it is probing the potential link between GM’s ignition-switch defects and a fatal crash in Canada in June 2013.

GM says in each of the fatal crashes, the air bags were not deployed.

Mai says he will be sending a letter to Raitt asking her to sit down at a meeting to answer questions the NDP has regarding the recall.

"At present, it is unclear when exactly Transport Canada was first alerted to the problem and what steps were taken to protect Canadians," he said.

GM says it will replace the faulty ignition switches for free. Repairs are expected to begin in April, when the replacement parts become available. Until then, GM is warning owners to remove all items from their key rings, including key fobs.