Two retired defence chiefs have urged the Government to scrap the Trident nuclear weapons system.

Lord Ramsbotham, a former adjutant-general who became the chief inspector of prisons, and Field Marshal Lord Bramall, a former chief of the defence staff, appealed to ministers to think again about their 2007 decision to renew Trident at a cost of up to £20bn. The money would be better spent on the precision weapons needed for current conflicts, they argued.

The two peers, who made their call in a letter in today's Times newspaper, said the weapons system was not an "independent" deterrent because Britain could never use it without the backing of the US. Lord Ramsbotham told BBC TV's Newsnight the decision to upgrade Trident was taken on political rather than military grounds. "It was a Cold War weapon. It is not a weapon for the situation we are now in," he said.

Download the new Independent Premium app Sharing the full story, not just the headlines

It would be of no value if Britain were subjected to "nuclear blackmail" by international terrorists, he added.