What had been the 2nd Armoured Division Support Group was now organized into four columns. The columns, as of 18 to 20 April 1941, each had a battery of field guns, some motor infantry, and anti-tank guns. They may have had one or two of the two-pounder anti-tank guns. The group would eventually become the 7th Support Group, for the 7th Armoured Division. The British were short of tanks at this point of time.
The defenses at Mersa Matruh depended on Australian anti-tank guns. The commander of the 2/2 Anti-Tank Regiment, Lt-Col. Monaghan, was responsible for the anti-tank defense at Mersa Matruh. The forward defensive front had two battalions. They were deployed near Halfaya Pass and both had Australian anti-tank gun support.
Rommel went forward to see the Halfaya Pass area for himself and saw the light forces holding the area. His immediate reaction was to get ready to attack the defenders. Rommel ordered a battery of medium guns to the area and ordered the Italian Trento Division to move to Bardia by 23 April.
When British intelligence had recognized that there were elements of the 15th Armored Division near Halfaya Pass, General Wavell became very concerned. So far, they had been engaged with the 21st Light Division, equipped to a lower standard than a regular armored division. Wavell knew that the British had two under-strength armored regiments in Tobruk and one squadron of cruiser tanks at Mersa Matruh. He calculated that the Germans currently had 150 tanks in Libya.
Wavell's message to London got the Prime Minister's attention. Churchill resolved to send a fast convoy through the Mediterranean, despite the risks. The ships would carry 250 tanks. They had mostly infantry tanks that could be sent, but they would try and find cruiser tanks. They ended up sending the first 50 Crusader tanks off the production line. Due to that situation, they were very unreliable, but they were something, at least. The Tiger Convoy, as it was called, would carry 295 tanks, of which 67 were cruiser tanks. This is based on the account in Vol.III of the Australian Official History.