However, in some cases exemptions were granted. The files provide an insight into the impact of World War I on families, businesses and communities far from the battlefields, and also lay bare the social tensions caused by the conflict, and the resistance of some men to serve.
The hearings were considered so sensitive that after the war, most files were destroyed.
In one case disclosed in the archives, the tribunal deciding on the case of Charles Rubens Busby, a butcher, was sent a letter signed only "a father and householder S H M", questioning why he had been allowed to keep his shop open and remain at home while "married men have had to shut up their shop and go".
The letter writer, a 68-year-old, said he had lost two sons in the fighting while Busby, 40, had made "heaps of money" and had deliberately joined a voluntary organisation to avoid being called up.
The butcher, who was described as "a proper rotter of a man" and a "rotten shirker", was accused of "bragging" about how he would not be called to fight, even taking bets on the matter.
Busby apparently lost his case and went to serve in the Royal Navy and Royal Air Force.
Others did have their exemptions granted, among them John Gordon Shallis who appealed on grounds of domestic hardship, having lost three brothers during the war.
Before the appeal was heard, a fourth had been killed. His parents, from Harlesden, also lost a son-in-law.
His mother is described as a "cripple" on his appeal form, having broken her leg, and his father was away carrying out Home Defence duties with the Territorial Force.
The chairman of the panel wrote they were "of the opinion that the mother is entitled to the comfort she will obtain by the retention of this last son". Given these exceptional personal circumstances and her son's employment within the munitions industry, he was granted an exemption from service.
Conscription was introduced in 1916, after the numbers volunteering fell to their lowest level and efforts to encourage more to enlist failed.
The records come from the Middlesex Appeal Tribunal which, between 1916 and 1918, heard appeals from local men who had applied for exemption from compulsory military service, and had already lost their first hearing. Those who lost again could make a further appeal, to a central tribunal, in London.
In the years that followed the war, the Government issued instructions to the Local Government Boards that all tribunal material should be destroyed, except for the Middlesex Appeal records and a similar set for Lothian and Peebles in Scotland.
The records have been published online as part of a series of projects to mark this year's centenary of the war's outbreak.
Pleas for exemption
Harry Ward
Describing himself as a foreign correspondent and book-keeping clerk, he resisted serving on conscientious grounds on the basis of his socialist beliefs. He lost his initial hearing after the chairman said that as a socialist he could not possibly have a conscience. The manner of this dismissal was raised in Parliament by an MP and Ward, 20, from Ponders End, north London appealed. He lost this hearing too, but later appealed to the central tribunal.
Frederick Lunkenheimer
The son of German migrants, he said his parents had fled Germany to escape military service and he had been brought up to think that "all warfare was wrong". The 20-year-old, from Acton, west London, said the family's shop had been "wrecked by the public owing to the bitter feeling against us being Germans. We were prevented from carrying on further business and grossly insulted in various ways." He applied to be exempted as a conscientious objector but had his appeal dismissed. He went on to serve with the Middlesex Regiment in a labour battalion which did not leave Britain.
Harry Harris
A 35-year-old from Wood Green, north London, he applied for an exemption so he could continue to run his grocery and general store, of which he was sole proprietor. He submitted a photograph of himself in front of the store as part of his appeal. He said he had to run it single-handed as all his assistants had gone to fight. If he were made to serve, he said, he risked losing his life savings. The tribunal dismissed his case, but gave him one month to make arrangements for the business.
Samuel Harrridge
A builder's labourer from Acton, he resisted conscription on the grounds that he had a brother in the army and was looking after his sister and widowed mother. The tribunal accepted evidence from a local military representative that the family would suffer "no serious hardship" should he serve, because the sister could "leave school and get employment".
Charles Horace Cunningham
He resisted conscription as a conscientious objector on the grounds of his Anglican beliefs and membership of the anti-war "Fellowship of Reconciliation" group. Cunningham, from Muswell Hill, north London, was initially granted an exemption on the condition that he remained in his job at London County Council. However, his employers suspended him without pay, on the grounds of his conscientious objector status. He kept his exemption after travelling to East Anglia to work as a farm labourer.
Aden Stone
A butcher from Ealing, west London, he appealed on economic grounds in order to look after his shop. An exemption was granted for one day, the shortest granted. The tribunal found Stone, 35, had bought out a competitor to increase his business needs and improve his chances of exemption.
