Britain's Cold War nuclear test veterans have been denied medals for their role in nuclear weapon tests.
About 22,000 servicemen took part in the UK's 1952-1967 atomic testing and radiation clean-ups in the Pacific and Australia, amid extremely dangerous circumstances, to secure the UK's hydrogen bomb.
The men endured blast yields detonated by Britain and the US of up to 7.7 megatons – far bigger than the explosions at Hiroshima and Nagasaki.
However, the independent Advisory Military Sub-Committee has unanimously decided not to award a medal to the veterans for their service.
The British Nuclear Test Veterans' Association (BNTVA) said the news was a "devastating blow to around 3-4,000 surviving nuclear test veterans with an average age of 85 years".
Watch: Atom bombs – a look at Britain's nuclear history.
Ceri McDade, CEO of the BNTVA, said the medal application was "to satisfy the committee with evidence of the risk and rigour they clearly endured at the testing".
"In 2013, the previous committee was satisfied that the element of risk had been met," she said.
"This committee states for a second time that their service was 'challenging', a word semantically linked with rigour, but still refuses to award a medal to these Cold War heroes."
Ex-veterans minister Johnny Mercer MP led the support for the BNTVA's application – submitted last June.
According to the BNTVA, it showed detailed evidence of the "clear bravery" of those involved and a "severe lack of health and safety" at the tests.
The charity also said it included "devious documented plans by the governments of the time in covering up dangerous levels of radioactive contamination".
Watch: UK's nuclear weapons programme £1.3bn over budget, watchdog warns.
This included case studies of the few remaining RAF cloud samplers, who flew directly through radioactive mushroom clouds.
It also contained excerpts from Second World War hero the late Captain John Gower, who, with his young crew, sailed through the radioactive plumes at Operation Mosaic numerous times.
This was not, however, enough to satisfy the Advisory Military Sub-Committee.
When asked for a response, a Government spokesperson said: "We are grateful to all those who participated in the British nuclear testing programme, which played a valuable role towards developing a nuclear deterrent that has ultimately kept Britain safe for decades.
"While it falls outside the criteria for medallic recognition, this in no way diminishes the contribution of those service personnel who witnessed the UK's nuclear tests."