Unexploded bombs should be detonated quietly to protect dolphins, the Government has recommended after a campaign led by Joanna Lumley.

The star and activist had teamed up with marine conservation charities to call for a change in the way unexploded war munitions found in the water are disposed of.

The Stop Sea Blasts campaign warned that detonating unexploded devices “causes huge disruption to marine habitats and threatens the survival of whales and dolphins”.

It called on the items to instead be burned using a technology called low-order deflagration, which involves a small magnesium cone being fired against the device – “causing its explosive contents to ‘burn out’ from the inside”.

This method sees the casing of the explosive crack open, but the munition does not detonate.

On Tuesday, the Government published a policy paper that stated: “Using alternatives to high order detonation as the primary method of clearance is preferred.”

The Government paper said it recognised that injury to marine species from noise associated with blasts and seabed disturbance are “key environmental concerns”.

It states that it supports the use of “lower noise alternatives”.

Ms Lumley, speaking as part of the Stop Sea Blasts campaign, said she was “thrilled” and described it as a “wonderful day”.

Ms Lumley said: “I’m thrilled that today the Government has, as far as I understand it, for the first time, clearly stated that using more environmentally friendly methods of clearing these unexploded bombs such as low order deflagration is the way forward.

“This is a victory for common sense.”

Lower noise alternatives are a ‘no-brainer’

At an event near Westminster on Tuesday afternoon, Ms Lumley said the deflagration method is 100 times less damaging and that both approaches “lie side by side on the shelf, they cost the same, they’re as easy to apply”.

She said using deflagration is a “no-brainer”, adding: “Why damage the environment when you need not damage the environment? It’s as simple as that – same cost, same results in the end.”

The unexploded devices often have to be cleared to make way for wind farms. A large number of explosives such as rockets, torpedoes and sea mines were left undetonated following the two world wars, and such devices must be safely cleared before construction of things like wind farms.

In March, Ms Lumley told The Telegraph that she had written to the Prime Minister and his wife, a well-known environmental campaigner, to object to the practice.

Last year, she joined conservation groups Marine Connection, the World Cetacean Alliance and Whale and Dolphin Conservation to call for the detonations to be halted.

“It’s crazy to me that wind farm developers, aided by government regulations that are far too relaxed, are able to just blow up bombs that are left over from the Second World War,” she said at the time.

A spokesman for the Department for Environment, Food and Rural Affairs said: “We absolutely recognise the impact that underwater noise from clearing unexploded ordnance can have on vulnerable marine species.

“We have made clear that our preference is for the use of quieter alternative methods, while ensuring measures are in place to protect both the environment and human safety, as trials are ongoing.”