Defence Secretary Bob Ainsworth let slip two opportunities to rescue a British couple kidnapped by Somali pirates.

Elite Royal Marine commandos were twice ready to launch a critical assault on the gang who had captured Paul Chandler, 59, and his wife Rachel, 55.

But each time Mr Ainsworth did not order the Royal Marines to move in. Nearly seven weeks later, the couple are still being held for a £4million ransom by the pirates. 

Ordeal: Rachel Chandler is menaced at gunpoint in a video released by her Somali captors. They are demanding a £4million ransom

The latest revelation implicated the Defence Secretary in the scandal for the first time.

It prompted calls for him to make a full statement to Parliament after a series of apparently misleading statements by the Ministry of Defence and Navy commanders.

The Royal Navy has already been heavily criticised over its failure to come to the aid of the Chandlers.

The couple, from Tunbridge Wells, Kent, were sailing from the Seychelles to Tanzania in their yacht, the Lynn Rival, when they were ambushed by armed pirates in a small boat 1,000 miles from Somalia on October 23.

They managed to send a distress signal, and the Wave Knight, a Royal Fleet Auxiliary vessel normally used to refuel Navy ships, was dispatched to intercept the pirates’ mother ship, the Koto Wajar, which was sailing to pick up the couple from the Lynn Rival.

When the Koto Wajar, itself a hijacked container ship, drew alongside the Chandlers’ yacht, the British vessel was 50 yards away.

The Wave Knight, which is under Navy command, had at least ten Royal Marines and an armed Merlin helicopter on board. The Marines, wearing black fatigues and carrying machine-guns, would have been able to attack the mother ship and leave the pirates stranded, too far from shore to return in their small boat. 

Threats: The couple were forced to plead for their lives saying their captors were running out of patience

But Navy commanders had to get direct permission to go in from the Armed Forces’ Permanent Joint Headquarters at Northwood, Hertfordshire. Mr Ainsworth was called because British civilian lives were at risk.

In a series of late-night phone calls, say senior sources, the Secretary of State discussed the unfolding stand-off with top brass under the command of Air Marshal Sir Stuart Peach, the current Chief of Joint Operations.

They sources said Mr Ainsworth was informed that Wave Knight had ‘engaged’ the 24,000-ton Koto Wajar by firing at it, but that the Lynn Rival, with the pirates and hostages aboard, was not in sight.

Mr Ainsworth twice could have ordered an assault by the Royal Marines. The commandos, trained in hostage rescue, were twice given the codeword Quickdraw  -  ‘ Imminent action’, but on both occasions were stood down.

Pressure: There have been calls for Bob Ainsworth to explain his role in the scandal to Parliament

They were forced to watch helplessly through night vision equipment as the terrified Chandlers were hauled on to the mother ship, which then sailed for the Somali port of Harardheere.

A source said: ‘The Navy has been in the firing line for not taking on the pirates, but the final decision not to use the Marines is out of our hands. It was taken at ministerial level after consultations with Joint Ops [Chief of Joint Operations].’

The decision was influenced by plans for a secret operation by the elite Special Boat Service which was already under way  -  even though they arrived two hours late. Mr Ainsworth was also told that although there were armed commandos within sight of the pirates, they did not have the ‘capability’ to deal with a hostage situation.

Mr Ainsworth’s direct involvement is the latest twist in the scandal. On October 29, the MoD said the Navy had found the Lynn Rival, but made no mention that the Wave Knight was 50 yards away as the Chandlers were taken off it.

On November 17, First Sea Lord Sir Mark Stanhope said the Wave Knight did not have ’special expertise to deal with hostage rescue’.

On November 29, it emerged that the Marine rescue force was on board, despite Sir Mark’s claims.

Liberal Democrat defence spokesman Willie Rennie said: ‘Bob Ainsworth must make a statement to Parliament explaining his role in this escapade.

‘It would be unfair and morally unjust for the Royal Navy to take the rap for something that is a political decision, especially when there were specialist troops on board.’

An MoD spokesman said: ‘The Secretary of State for Defence and First Sea Lord are clear that they gave the go-ahead for the operation to take place; and that having done so it was entirely proper for those responsible for carrying out the operation to make tactical level decisions in the knowledge that they had the full confidence and backing of both the Secretary of State and the First Sea Lord.

‘It was not for them, based in London, to second-guess decisions made by forces in the field.

‘They are confident, however, that those in command of this mission did exactly the right things.

‘As in all situations, those responsible for carrying out the operation had to balance capabilities and possible actions against the risk to life. Could action have been taken, with a guarantee on the safety of the Chandlers, they would have done so.

‘They are also both clear that the decision not to intervene was unquestionably the right one in the circumstances.’