New designs and improved versions of the existing vehicles developed in response to the appearance of the T-34 and KV not only made German tanks more than a match for the Soviet tanks in terms of gun-power but also put them well ahead of British and US tanks. So far as British tanks were concerned, the 40mm guns of the early cruiser tanks, from the Mark I to the Mark VI Crusader, and of the Matilda infantry tank, were superior in terms of armour penetration to the 37mm gun of the original Pz.Kpfw.III and almost equal to its short 50mm gun.
However, no attempt was made in Britain to develop a tank with a larger calibre dual-purpose gun like that of the Pz.Kpfw.IV. What was developed were only close support versions of the cruiser and infantry tanks armed with 76.2mm howitzers, which were limited-purpose weapons with no armour piercing capability and which were in no way comparable to the dual-purpose guns of similar calibre mounted at the time in Soviet as well as German tanks.
A larger, 57mm gun was mounted in 1942 in the Crusader VI cruiser tank and Churchill III and IV infantry tanks. Its armour-piercing capabilities were considerably greater than those of the 40mm gun and almost the same as those of the long 75mm with which Pz.Kpfw.IV had been rearmed by then. But it was still inferior to the latter, and other 75 or 76mm guns, so far as high explosive shells were concerned. Moreover, there was no British tank with a more powerful gun that could match the 88mm gun of the Tiger, which had appeared in 1942.
In fact, cruiser and infantry tanks continued to have exactly the same main armament, in spite of the considerable differences in their weight. This meant that the heavier, infantry tanks could not play a role equivalent to that of the heavy tanks of the German and Soviet armies, which were not merely more heavily armoured than the medium tanks but which were also armed with much more powerful guns. As it was, they were never expected to be a more powerfully armed complement to the cruiser tanks. Instead, they were intended to form a separate category of tanks for close cooperation with the infantry and for this purpose they were much more heavily armoured than the cruiser tanks but not more heavily armed. Thus, as a contemporary War Office publication put it, "The main difference between the infantry and cruiser tanks lies in the thickness of armour".
The concentration on armour protection in the development of the infantry tanks paid off at first in the case of the Matilda, which enjoyed a high degree of immunity when it was used in 1940 and 1941 in Africa against ill-equipped Italian forces. But, based as it was on armour protection, its success was cut short, like that of the Soviet KV, by the appearance of more effective anti-tank weapons. Thereafter it had to rely more on its armament and in this respect it was no better than the contemporary cruiser tanks. The same was true of its successor, the Churchill infantry tank, whose armour was progressively increased to a maximum of as much as 152mm but which, in spite of it, did not distinguish itself as a fighting vehicle.
In 1943 it was finally recognised that tank guns should not only be armour-piercing weapons but dual-purpose guns capable of delivering effective high explosive fire as well as perforating the armour of enemy tanks. Thus the final, 40 ton version of the Churchill and the 28 ton Cromwell cruiser tank were both armed with medium velocity 75mm guns. But when these tanks went into action in 1944 their armament was two years behind that of the Pz.Kpfw.IV and three behind that of the T-34. Moreover, they were no longer powerful enough to fight effectively the latest types of the opposing tanks, such as the Panther or, even more, the Tiger.
The official attitude towards this situation was that "the tank is designed with the primary object of destroying or neutralizing enemy unarmoured troops". This may have been true during the First World War but the view implied by this statement that tanks should not normally fight enemy tanks was no longer realistic when both sides were using tanks on a large scale and fighting them could not be avoided. Nevertheless, such views persisted and so did the policy, of which they were an expression, of developing and using the two separate categories of infantry and cruiser tanks.
This policy was, in fact, the root cause of the inadequate attention given to the gun-power of British tanks and of their shortcomings during the Second World War. How serious these shortcomings were is indicated by the fact that, in spite of the relatively large number of tanks produced in Britain, in 1943 and 1944 British armoured formations had to be equipped to a large extent with US built tanks. Yet in 1941 British tank output was already considerably higher than the German and at its peak of 8611 in 1942 it was more than double the latter.