A CND campaigner on Trafalgar Square in 2004 protests against the planned replacement of Britain's Trident nuclear systems. A report by an anti-nuclear group claims that the government has bypassed parliament to go ahead with the proposals. (ALESSANDRO ABBONIZIO/AFP/Getty Images)The capacity to test nuclear weapons in the laboratory without the need for underground explosions is being developed by the British government, undermining its commitment to a test ban treaty, claims Greenpeace.

The report by the environmental action group follows speculation over investment in new technology at the Atomic Weapons Establishment (AWE) at Aldermaston.

"The U.K. investment program at Aldermaston is turning the comprehensive test ban treaty into a hollow shell that allows those states with advanced technology to develop new nuclear weapons without nuclear testing," states the report.

The claims threaten to undermine the Prime Minister's earlier promise to MPs that before any action was taken on replacing Britain's Trident nuclear system there would be a proper debate in parliament.

A spokesman for the Ministry of Defense (MoD) denied the allegations. "I can be absolutely clear no decision has been taken to replace Trident," the spokesman said. "However, we have promised a White Paper, a parliamentary debate, and a vote if any decision to replace is made."

Following the 2005 election, the government recruited 90 scientists, 250 engineers, 57 technical support staff, and 98 business services staff to work at Aldermaston. There are also plans to recruit an additional 700 staff by the end of next March.

The government has claimed that the increased funding and staff at Aldermaston are merely to keep up the existing nuclear systems, rather than develop new technologies.

In 2005 Defense Secretary John Reid said: "The purpose of this investment of some £350 million [US$656 million] over each of the next three years is to ensure that we can maintain the existing Trident warhead stockpile throughout its intended in-service life."

However, in 2002 AWE stated on its Web site that it hoped to develop the capacity to build a successor to Trident "without conducting nuclear tests."

"Our research and development work splits into two main but inter-related areas," a statement by Dr. Clive Marsh, AWE's Chief Scientist on the Web site also said. "The first is the requirement to maintain the current Trident stockpile. The second is to develop our overall warhead design and assurance capabilities, including the ability to provide a new warhead lest our government should ever need it as a successor to Trident.

"Most of our research is conducted in this capability area."

New facilities include the high-powered Orion laser, supercomputers that can be used to model explosions, and hydrodynamic facilities that study how plutonium reacts when blown up with high explosives.

Greenpeace claims that these technologies give the government the capacity to test new types of nuclear weapons in controlled laboratory conditions rather than in underground bunkers, as was the case in North Korea two weeks ago.

They claim that the nuclear weapons stockpile during the Cold War was maintained through "curatorship," that is, the routine checking and replacement of all components of the missile itself.

But a MoD spokesman disputed that the systems could be maintained solely by curatorship. "It is wrong to claim you can simply maintain nuclear weapons off-plan, the materials used do deteriorate and change with time."

At present only five states—Britain, the U.S., Russia, China, and France—are able to hold nuclear weapons under the nuclear non-proliferation treaty (NPT).

As a way of appeasing the world's non-nuclear states, the major powers signed the comprehensive test ban treaty (CTBT), which banned nuclear underground testing.

Under this treaty, states are effectively unable to develop new and more destructive weapons—an agreement which Greenpeace fears will be lost if the government replaces Trident—whether now or later.

Moreover, Greenpeace claims that it is unlikely that any rational government would be willing to replace its established and tested nuclear weapons with warheads which are only proven to work theoretically.

This would therefore create pressures to resume underground testing, a development which could in turn antagonize non-nuclear states.

Should this be the case, it would be likely that the NPT would collapse and rogue states such as North Korea and Iran could pursue their own nuclear programs at the expense of international law.

"Building new nuclear weapons at a time when the U.K. faces no foreseeable nuclear threat and when the international community is trying to prevent other countries developing their own is incredibly inflammatory," said Greenpeace Campaign Director Blake Lee Harwood.

Still, the government says it remains committed to the NPT and points to how it has reduced its stockpile of available warheads to less than 200, a 70 percent reduction since the end of the Cold War.

"Britain remains committed to achieving a world in which there is no place for nuclear weapons, and when we are satisfied with progress towards this goal, [we] will put our remaining nuclear weapons into the negotiations," the MoD spokesman said.

"But the prime minister has made clear that nuclear disarmament must be undertaken through a process of international negotiation, and no timetable for such negotiations has yet been agreed."