For years UK ministers have repeatedly refused to say where neutron generators - a vital component of the Trident warheads stationed on the Clyde - were manufactured. The information had to be kept secret for national security reasons, they said.
But now, confronted with undeniable evidence by the Sunday Herald, the MoD has admitted that the devices are imported from the United States. And in so doing, it has opened the Westminster government to a barrage of criticism from experts, politicians and campaigners.
“This is another deceit of the British public by Westminster,” declared Dan Plesch, director of the Centre for International Studies and Diplomacy at the University of London.
“It’s another smoking gun in the arsenal of evidence that shows that there is no such thing as a British bomb. The weapon will become unusable should the Americans withdraw their support,” he said.