The Ministry of Defence yesterday said the addition of 2,000lb bombs to the weaponry of the RAF was set to boost capabilities for missions over Libya.
The Enhanced Paveway III (EPWIII) bombs are designed to penetrate the roof or wall of a hardened building, enabling the RAF to attack structures in Libya like command centres or communications nodes.
But the use of bombs to target difficult structures such as bunkers is not without controversy. In Iraq, during the Gulf War in 1991, US bombs hit the Al-Amiriya air raid shelter in Baghdad and were said to have killed hundreds of civilians.
The Ministry of Defence yesterday said targets such as command and communications centres were key to disrupting the Gaddafi regime's control of its forces, preventing attacks which could target civilians.
Defence Secretary Dr Liam Fox said: "The introduction of Enhanced Paveway III bombs is another way in which we are developing our tactics to protect civilians and achieve the intent of United Nations Security Council Resolutions 1970 and 1973.
"We are not trying to physically target individuals in Gaddafi's inner circle on whom he relies, but we are certainly sending them increasingly loud messages. Gaddafi may not be capable of listening, but those around him would be wise to do so."
The EPWIII will be added to the existing weapons carried by the RAF's Typhoon and Tornado aircraft, including Enhanced Paveway II, Paveway IV, and Dual Mode Seeker Brimstone.
The MoD said the first set of EPWIII bombs had been prepared and could be loaded on to an aircraft and flown to attack a Gaddafi regime target in Libya in a matter of hours.
Dr Fox yesterday said that Nato continues to face an "absolutely vital" task in protecting Libyan civilians from the brutality of Gaddafi. He acknowledged the "increased risk" attached to the deployment of attack helicopters, but stressed that they would play a key role in bringing a halt to the dictator's attacks on his own people.
RAF Apache helicopters will form part of the latest Nato deployment in a move that has alarmed some MPs about the prospect of an escalation in the conflict and the danger to British lives.
Dr Fox denied that it amounted to an "escalation", but said: "It's quite right that if we use attack helicopters there is an increased risk - they fly at far lower heights than fast jets would, obviously at slower speeds than the fast jets would, and they are more susceptible.
"That's why in taking that decision we have looked at all the variables, the risk to our service personnel which is always very key, but also the fact that we are making progress in Libya, it's clear the regime is having trouble sustaining military activity and the more we can degrade that the more we can protect the civilian population.
"What people seem to be forgetting at the moment is that our primary job is protecting the civilian population and Gaddafi is still attacking the civilian population, so the task remains an absolutely vital one."
He insisted there was "no question whatsoever" of ministers overriding military concerns about the deployment of helicopters. Nato's determination to avoid civilian casualties as much as possible has prevented speedier progress in Libya and Gaddafi is thought to be moving between hospitals in a bid to keep himself safe from air strikes.
Dr Fox said: "He's got a lot of bunkers, there are a lot of facilities that are being used partly as accommodation, but also largely for military control and we will continue to degrade that."The Defence Secretary denied that the military was targeting Gaddafi personally, saying: "We are trying to degrade his ability to control his armed forces and those who are repressing the civilian population."
Asked whether he was confident Gaddafi would go in the end, he added: "It's clear that the international community believes it's not possible to protect the civilian population while Gaddafi remains in control of the regime.
"He will go sooner or later and the calculation for those around him is how long they continue to invest in someone who ultimately will be a loser."
On the ground in Libya, forces loyal to Gaddafi cut electricity supplies to much of the Western Mountains, threatening water supplies and stepping up a war of attrition with rebels who hold the plateau.
The blackout, which began five days ago, has coincided with an increase in shelling of the rebel command centre of Zintan and the town of Arrujban.