On Saturday morning five precision-guided Paveway IV bombs were dropped on the Baroni Centre, a secret intelligence base headed by Gaddafi’s brother-in-law Abdullah Senussi.

The aircraft then struck at least one main battle tank belonging to Gaddafi’s troops, and in the afternoon another RAF patrol destroyed an artillery piece on the western edge of Tripoli and a nearby command and control facility.

On the ground, the rebels had spent weeks smuggling weapons, communications equipment and battle-hardened fighters into Tripoli, setting up secret arms dumps around the capital and waiting for a pre-arranged signal to trigger the uprising.

Mahmoud Shammam, a spokesman for the TNC, told the Daily Telegraph that the agreed signal was a televised speech by the TNC chairman, Mustafa Abd-al-Jalil, which was broadcast via the Qatar-based Libya TV on Saturday evening.

Mr Jalil told the citizens of Tripoli “you have to rise to the event”, and as dusk fell at around 8pm local time a group of rebels seized their chance and took control of the Ben Nabi Mosque close to the city centre.

Using loudspeakers which normally call people to prayer, they began anti-Gaddafi chants to confirm the start of what rebel leaders called Operation Mermaid Dawn – the battle for Tripoli, which is nicknamed Mermaid in Arabic.

Mr Shammam said: “The start of the uprising was pre-arranged. We used our TV station for Mr Jalil to give a speech calling for the uprising and soon most of the people of Tripoli were on the streets.”

The timing of the uprising caught Gaddafi completely by surprise; the rebels had spent that day flushing out that last of his forces from Zawiyah, 30 miles west of Tripoli, and the Brother Leader had clearly expected them to regroup, reorganise and re-arm - as they had done in the past after each major battle - before making an attempt on Tripoli.

Instead, the rebels who had been fighting in Zawiyah were making a dash for the capital, and in the skies overhead RAF Tornados and Typhoons were launching further surgical strikes on pre-planned targets.

The RAF and its alliance partners carried out 46 sorties on Sunday alone, relying heavily on the RAF’s Brimstone ground attack missile system that can pick out targets close to civilian areas with incredible accuracy, minimising the risk of civilian casualties.

Gaddafi’s bunker at Bab al-Aziziya was pounded throughout the night, and the Tornados’ advanced electronics also enabled aircraft already in the sky to hit Gaddafi targets as they were identified, using a system known as dynamic targeting.

Gaddafi’s command and control centres, set up in industrial buildings or even empty schools, were also attacked, crippling the Libyan despot’s ability to direct his troops.

On the ground, meanwhile, the rebels sent out mass text messages to regime opponents waiting in Tripoli for a signal to rise up, and as Gaddafi’s forces tried in vain to suppress the revolt it spread out across 13 suburbs.

By Sunday afternoon the rebels who had been fighting in Zawiyah were just miles away from the outskirts of Tripoli.

William Hague, the Foreign Secretary, confirmed yesterday that Britain had equipped the fighters with a range of “non-lethal” kit including advanced telecommunications equipment and 1,000 sets of body armour.

They had also been given night vision goggles, which proved crucial in picking out snipers who had been sent by Gaddafi to impede their progress towards the capital.

The battle plan also included a sea-borne assault on Tripoli launched from the port of Misrata to the east, which landed at dawn on Sunday.

Gaddafi took to the airwaves to make a series of increasingly desperate appeals for Libyans to defend Tripoli from the rebels as “a matter of life and death” but the crackling recordings of his voice – and a lack of any video footage – led to speculation that he had either fled the country or had gone into hiding in a 2,000-mile network of tunnels built in the 1980s.

His soldiers, sensing the battle was lost, had begun dumping their uniforms wherever they stood, and by midnight on Sunday the rebels had reached Green Square, the symbolic heart of Tripoli, with little resistance.

The speed of the rebel advance was such that Gaddafi’s intended heir, his son Saif al-Islam, had no time to reach his father’s compound, and was captured by rebels on Saturday night.

His brother, Mohammed, was giving a telephone interview to a broadcaster when a gunfight broke out inside his home. The line went dead and seconds later he too was captured.

Mr Shammam said: “The plan was very successful. Our assumption was that it would take a few days but the results were clear in a few hours.

“We were expecting more resistance from Gaddafi’s troops. We thought they were determined to fight to the last moment but it seems like they got tired or lost the cause.”

David Cameron, who was on a family holiday in Cornwall, also seemed to have been caught out by the rapid turn of events.

Although he had been kept up to date with the rebels’ plans, no-one had expected Tripoli to fall so quickly, and the Prime Minister scrambled to get back to Downing Street to chair a meeting of the National Security Council yesterday.

Speaking outside Number 10, he paid tribute to the “incredible bravery, professionalism and dedication” of the RAF pilots, adding: “This has not been our revolution, but we can be proud that we have played our part.”

As the fighting continued in Tripoli last night, the rebels had gained control of around 90 per cent of the city, with the bloodiest battle raging around Gaddafi’s compound at Bab al-Aziziya.

Another of Gaddafi’s sons, Khamis, was reported to have led his eponymous Khamis Brigade into battle from the compound, killing what one official described as “a big number” of rebels.

Tanks rolled out of the compound to begin shelling the city, and snipers fired from rooftops to prevent rebels joining the battle at Bab al-Aziziya.

Loyalist tanks were also deployed at the port, but the rebels continued to press on, and scored further victories.

By mid-afternoon yesterday they had reportedly captured a third son of Gaddafi, Saadi, and at 4pm Libya’s state broadcaster went off the air, removing one of the despot’s final and most important tools in his ability to maintain any form of resistance.

Across Tripoli, its citizens tore down every green flag of the Gaddafi regime they could find, chanting “freedom” in English. By last night, Green Square had been renamed Martyrs’ Square as 42 years of tyranny finally came to an end.

“We came out today to feel a bit of freedom,” said Ashraf Halaby, 30, as he joined the celebrations in the square. “We still don't believe that this is happening.”