Joanna Lumley and Kelly Holmes among stars demanding PM delivers justice for Britain's nuclear test veterans

He must “begin without delay an urgent process to bring truth and justice, so that they can get the answers and accountability they have been denied for so long,” they say.

In the 1950s and 60s, more than 22,000 British servicemen and scientists were knowingly exposed to high levels of radiation as Britain conducted its atomic tests in the Pacific and Australia.

Without protection, both the veterans and generations of their families have suffered numerous health consequences.

In their letter seen by GB News, the stars write: "The average veteran is now in his late 80s or 90s. There is no time for this to become another promise that quietly disappears now you're in office.

“It must be done properly, and it must be done quickly.”

The letter comes just days after representatives from campaign group LABRATS International met Mr Burnham for the first time since he became Prime Minister.

Also attended by the Defence Secretary, Wes Streeting, campaigners called the meeting “a very productive day”.

Representatives from campaign group LABRATS International met Andy Burnham for the first time since he became Prime Minister

X/ANDYBURNHAM

The Prime Minister, who has previously called the nuclear tests "a criminal cover-up on an industrial scale," said he was committed to working together on next steps.

Reacting to the celebrity endorsement of their fight for justice, Alan Owen, co-founder of LABRATS and son of a nuclear test veteran said: "To have the backing of such well-known and respected faces has given the veterans a big morale boost!

“We have been campaigning for three generations now. Many veterans have grandchildren who are also facing health impacts that have been passed down. But despite decades of cover-up by the MoD, we have never given up our fight.

"There really is no time to waste. We are putting our faith in Prime Minister Andy Burnham to begin a fair, thorough and urgent process that will deliver truth, justice and accountability.

“It needs to happen without delay, while veterans are still alive to be a part of it. It is the least they deserve."

READ THE STARS' LETTER TO THE PRIME MINISTER IN FULL:

Dear Prime Minister,

In the 1950s and 60s, thousands of British servicemen and civilians were ordered to participate in nuclear tests in Australia and the South Pacific. They were given no protection, and nobody warned them of the harm it would cause.

Since then they have suffered lifelong health conditions, and many of their children and grandchildren have also been affected. They have spent the decades since fighting for the truth: for their exposure to nuclear radiation to be acknowledged, their illnesses recognised, and their medical records released. Many have died waiting.

You know this story better than most. As an MP and Mayor of Greater Manchester, you said what they had gone through was "a criminal cover-up on an industrial scale," and you called for justice for our Nuclear Test Veterans. In your first speech back in Parliament, you backed the special tribunal they have spent years fighting for.

Now you have the power to deliver it. In signing this letter, we are showing our solidarity and support for the Nuclear Test Veterans. We call on you to honour the commitment you made to them. You must begin without delay an urgent process to bring truth and justice, so that the veterans can get the answers and accountability they have been denied for so long.

The average veteran is now in his late 80s or 90s. There is no time for this to become another promise that quietly disappears now you're in office. It must be done properly, and it must be done quickly.

Yours sincerely,

Dame Joanna Lumley - Actor and Activist;

Dame Kelly Holmes MBE (mil) OLY - Olympic Gold Medalist, formerly served in the Army;

Levison Wood - Explorer, former Captain in the Parachute Regiment;

Sue Holderness - Actor, supporter of armed forces and veterans charities;

Antony Cotton - Actor.