Putting female soldiers on the front line is a "social engineering experiment" that will be paid for "in blood", a former British military chief has said.
Former Colonel Richard Kemp, the commander of British forces in Afghanistan in 2003, said that women - who are currently unable to join infantry battalions - will become a "weak link" if they are allowed to join front line units.
In an article in The Daily Telegraph he blamed "politicians desperate to be seen as 'progressive', feminist zealots and ideologues hell-bent on equality of opportunity without exception" for pushing ahead with the planned move.
His comments come after it was reported by The Sunday Times that the army is amending its fitness tests to recognise the differences between men and women.
But General Sir Nick Carter, chief of the general staff, told the newspaper that there would be "no lowering of training or qualifying levels for soldiers in ground close combat roles".
A review is currently under way to decide whether both sexes can fight together and Penny Mordaunt, Britain's first female Armed Forces Minister, has insisted that women can make the grade.
Col Kemp condemned plans to change physical fitness standards as "dangerous".
Only a small number of women will want to join the infantry and fewer still would have the physical capability, so a lowering of standards was inevitable, he said.
He also claimed that soldiers are unhappy with the potential change which would put lives in danger.
He said: "The overwhelming majority are vehemently opposed and many have said that if women join they will leave.
"Why do feelings run so high? Because every infantryman knows that the price for this social engineering experiment will be paid in blood."
Col Kemp has previously argued that women lack the "killer instinct" necessary to fight in close combat.