March but progress over the next four days against the 164th Light Afrika Division and 21st Panzer Division was very slow, although they did secure the entrance to the gap. On the Mareth Line, XXX Corps made some progress but did not break through. On 23 March, Montgomery ordered the 1st Armoured Division of Major-General Raymond Briggs of X Corps to reinforce the New Zealand Corps from reserve, where it was waiting to exploit the anticipated breakthroughs by either XXX Corps or the New Zealand Corps and Horrocks, with the X Corps Headquarters to take control of operations in the Tebaga Gap. Operation Supercharge II Operation Supercharge II was planned to start on the afternoon of 26 March, with a preliminary operation on the night of to capture Height 184. The New Zealand Corps was to attack into the Tebaga Gap on a two-brigade front and capture the Axis defences from Djebel Tebaga to Djebel Melab, which would be exploited by the 1st Armoured Division. After assembling during the night and lying in concealed positions all day, the 5th New Zealand Brigade was to attack on the right and the 6th New Zealand Brigade on the left, preceded by the 8th Armoured Brigade and a creeping barrage by the New Zealand and X Corps artillery. The attacking troops were to move to high ground forward and then to a second objective at a wadi further on. The 1st Armoured Division, led by the 2nd Armoured Brigade, was to move through at to an area beyond the New Zealand Corps final objective and as soon as the moon rose (at about advance on El Hamma. RAF heavy bombers would begin harassment of the Axis defenders led by General Messe the night before, with attacks on transport and communications until Day bombers would then begin low-altitude pattern bombing, to add to Axis disorganisation, followed by relays of fighter-bombers every for hours. Spitfires would escort the bombers and fighter-bombers and the remainder of the Northwest African Tactical Air Force (NATAF) would bomb Axis airfields. An RAF forward observation officer was to brief pilots by nominating landmarks, marking targets with red and blue smoke; friendly troops were to use orange smoke and the artillery would fire smoke shells to signal to the aircrews. On 24 March, Arnim doubted that an Eighth Army attack was likely and was more concerned about Maknassy further north. Despite