Although formally presented as an amendment of the Defence of the Realm Act 1803, it was actually a major piece of new legislation as it required counties in Great Britain to draw up lists of men for military training and detailed how compulsory training would take place.

However, the Act included clauses that military training could be suspended if sufficient numbers of men joined volunteer corps, and the huge increase in their number in response to the Act meant that compulsory military training was never used.

The Act revived the idea of posse comitatus and detailed mechanisms for military training in each parish in Britain.

[1] It stated that lords-lieutenant and their deputies should list all men between seventeen and fifty-five except clergymen, Quakers, schoolmasters, and the infirm.

3 c. 120), passed on 11 August, which stated, amongst other things, that if the number of volunteers in any county was satisfactory to the King he could suspend the operation of the Levy en Masse Act even if they did not amount to the three-fourths of the first classification.