While the rest of the regiment remained in AA Command during the Phoney War period, 43 (CoLY) LAA Bty, then at Chingford and Great Bromley, left on 15 February, and along with 44 LAA Bty from 12th (Finsbury Rifles) LAA Rgt it joined 60th (Royal Welch Fusiliers) Anti-Tank Rgt to form 101st LAA/AT Rgt. This composite unit, the first of its kind, was part of 1st Support Group (1st Sp Gp) in 1st Armoured Division, which was rushed to France to join the BEF after the German invasion of the Low Countries. Armed only with Lewis guns, its Bofors not having arrived, 43 (CoLY) LAA Bty fought in the Battle of Abbeville as 1st Armoured Division attempted to break through to the surrounded BEF. The division was evacuated from western France two weeks after the rest of the BEF had been evacuated from Dunkirk.