They are the unsung heroes of the Second World War.
Men, and sometimes women, who served in the pits, in munitions factories and on the railways played a vital role in the fight against fascism.
And because their work was essential, they were barred from signing up in the armed forces.
Once the war was over, a grateful nation paid thanks to the soldiers, sailors and airforce personnel who fought for their country but the contribution of men who kept Britain’s war machine running at home has not received the same recognition.
Now, MPs are hoping to change that, by calling on the Government to find a way of marking their contribution.
Blaydon MP Dave Anderson, Blyth Valley MP Ronnie Campbell, North Tyneside MP Mary Glindon and Wansbeck MP Ian Lavery are among MPs who have signed a House of Commons motion calling for the creation of a royal commission to examine how this can be done.
It follows the success of a campaign to calling for national recognition of the contribution made by the Bevin Boys - young men who were conscripted to work in the coal mines during the war. Their nickname was a reference to the Minister of Labour at the time, Ernest Bevin.
A memorial to the Bevin Boys was recently unveiled at the National Arboretum in Staffordshire in recognition of their role in serving their country.
But the MPs argue that five million workers in reserved occupations were in the same position, except that they happened to be working in essential jobs already rather than being conscripted in.
Mr Campbell said: “There are a lot of old miners still around who couldn’t get out of the pits.
“If the Bevin Boys had the recognition because they had to go down the pits to get the numbers up then the lads that had to stay down the pits are the same class of people.
“A lot of them were miners and there were other occupations as well.”
Reserved occupations were introduced in an attempt to avoid the mistakes of the First World War, when the recruitment of too many men into the military had left major war production schemes short of the necessary workforce.
A Schedule of Reserved Occupations covered five million men in a vast range of jobs including railway and dockworkers, miners, farmers, schoolteachers and doctors.
Many people in reserved occupations joined civil defence units such as the Home Guard.