Environment Minister Peter Kent appeared before MPs at an after-hours sitting of the House of Commons Tuesday night, fielding questions on his department for four full hours.

Every year, the Official Opposition gets the chance to bypass the usual committee review and send the main estimates for two departments to Committee of the Whole, which is, basically, all interested MPs meeting in the House of Commons with the Deputy Speaker presiding.

Over the course of two sessions, the relevant ministers present themselves and spend the next four hours fielding queries on their respective departments' main budgetary requests for the next fiscal year. This year, the NDP, as the Official Opposition, chose to hear from the Environment Minister and Defence Minister Peter MacKay. MacKay went last week and it was Kent's turn Tuesday.

The format is more like a committee meeting than a regular House sitting: Ten minutes allowed for statements, and 15-minute slots for MPs in a rotation by party. Given the broad scope of subject at hand, members are generally given considerable leeway to question the ministers on a wide range of issues — subject, of course, to the rulings of the chair.

Tuesday's appearance by Kent was delayed by several votes in the House of Commons but got underway about 9:30 p.m. ET and ran until the wee hours Wednesday.

The CBC's Kady O'Malley watched the proceedings. Read a recap of her liveblog below.

Mobile users, follow the liveblog here.