A ban on women serving in close combat units in the British military has been lifted by Prime Minister David Cameron.
But the Army's research suggests fewer than 5% of its 7,000 women would pass the current infantry fitness test.
'World-class'
The PM's decision follows a government review in which the head of the Army, General Sir Nick Carter, recommended the ban should be lifted.Announcing the move at a Nato summit in Warsaw, Poland, Mr Cameron said: "It is vital that our armed forces are world-class and reflect the society we live in.
"It will ensure the armed forces can make the most of all their talent and increase opportunities for women to serve in the full range of roles."
The opening of roles for women in close combat are expected to be phased, initially with positions in cavalry and armoured units and then to the infantry.
Concern over the issue had centred on whether women had the physical capability to withstand the demands on their body that some of the roles will require.
The basic fitness tests for the infantry involves recruits completing an eight-mile march in under two hours while carrying a backpack weighing 55lbs (25kg).
There is also an advanced fitness test of marching two miles carrying 20kg in 18 minutes, and further two-part test of 20 miles carrying 25kg in five hours, followed by 25kg over 25 miles in six hours and 15 minutes the following day.