the day after the falklands invasion by Argentina, parliament was recalled to emergency session, the first time this had occurred on a saturday for many years. parliamentary proceedings were available to radio broadcasters, and i listened along with students at Bradford Uni. the transcript is here:-
https://api.parliament.uk/historic-hansard/commons/1982/apr/03/falkland-islands
most illuminating is the speech at 11h45, delivered by Michael Foot, MP for Ebbw Vale and at the time, leader of the opposition, and the winding up speech by John Nott at 1h45. neither the government as a whole, nor the prime minister individually, acted unilaterally; instead the military action that followed had the full support of the opposition, as delivered by John Silkin, shadow leader of the house.