A number of alien labour units were established in the British Army's Middlesex Regiment during the First World War.

There was some criticism in the House of Commons over the decision to deploy the men abroad and the length of time it took to demobilise them after the war.

During the early part of the First World War aliens (i.e. foreign nationals) of hostile states, such as the Central Powers, were relatively unaffected.

[2] The rise of anti-German sentiment after the 7 May 1915 sinking of the RMS Lusitania saw the implementation of a general internment programme for aliens from hostile states.

[1] Army Council Instruction 1209 of June 1916 attempted to provide a solution; a non-combatant labour unit was to be established to accept such citizens.

He noted that many serving soldiers were unaware of it and that the parent regiment did not want to be associated with what had been described as a "foreign legion" and nicknamed the "Kaiser's Own".

[7] By early 1917 the British Army was beginning to be hampered by a shortage of labour on the lines of communication leading to the Western Front.

Because of a perceived security risk the alien labour companies were not permitted to remain for more than a few days at base depots: drafts passing through and separated men were prioritised for transport to their units.

The Under-Secretary of State for War, the Liberal Party's Ian Macpherson, replied that no such promise had been made and that the unit was non-combatant in nature.

He noted that many of the men's fathers were interned as enemy aliens and some had brothers or other relatives serving in the armies of the Central Powers.

He restated that he had been told the men had been promised they would serve only in Britain and that he had now heard that an NCO of the unit had lost his rank for protesting against their deployment.

The non-Russians of this category were assigned to the Middlesex Regiment, allowing additional labour companies to be formed.

The Secretary of State for War, Winston Churchill, replied that they were being treated the same as other army personnel when it came to eligibility for demobilisation.