At the end of May 1940, with the British Expeditionary Force being evacuated from Dunkirk and the imminent threat of German invasion of England, 25th Army Tank Brigade was redesignated 2nd Motor Machine Gun Brigade and its regiments reorganised accordingly. Each MMG squadron consisted of three troops, each with six Austin Utility ('Tilly') two-seat cars, two carrying medium machine guns, two Bren light machine guns and two Boys anti-tank rifles. In July 1940, volunteers from the units of 25th Army Tank Brigade formed No. 5 Troop of No. 5 Commando at Bridlington.