Until then an interim design based on the A27 to replace the Churchill as an infantry tank was considered.

English Electric, contracted to build Cromwells, proposed using the A27 hull and turret with extra armour[note 1] and the track and suspension of the 50-ton US M6 Heavy Tank which had been developed for both US and British use.

The second was built with a widened Cromwell track and suspension by LMS and different armoured skirts.

The design included extra armour and an Ordnance QF 75 mm gun.

When the problems of the early Churchill models were worked out, the A33 was no longer required and the project was dropped.