Fallout: the veterans who dropped a nuclear bomb on the Ministry of Defence

"Hello," said the Ministry of Defence press officer. "We noticed you had quite a good day in Parliament. Are you doing a story?"

There is nothing quite so welcome to a journalist's ear as an unsolicited phone call from worried authority. And in this case, they had reason to panic. Because the Mirror had just made history.

When a MP has a crusade they often hire a committee room and ask their colleagues to pop along for a picture, to show support. You're lucky if more than 6 MPs find the time to locate the right corridor and poke their head around the door to say hello. Deputy Labour leader Tom Watson did it on Wednesday as part of our campaign to demand a medal for heroes of our nuclear bomb tests.

After the 8th MP, photographer Ian Vogler turned to Alan Owen, chairman of the British Nuclear Tests Veterans' Association, and said: "Well, that's your lot. Pretty good show."

But they kept on coming.

In the heart of Parliament sits Westminster Hall, the 921-year-old, ancient space with a hammerbeam roof and so much history in it you can almost see it ooze from the 6ft-thick walls. This is where Thomas More stood trial, Charles II held his restoration banquet, where Anne Boleyn appeared in pomp at the height of her power.