Royal Navy vessels are being readied to take part in a possible series of cruise missile strikes, alongside the United States, as military commanders finalise a list of potential targets.

Government sources said talks between the Prime Minister and international leaders, including Barack Obama, would continue, but that any military action that was agreed could begin within the next week....

The Assad regime has been under mounting pressure to allow United Nations inspectors on to the site to establish who was to blame for the atrocity. One international agency said it had counted at least 355 people dead and 3,600 injured following the attack, while reports suggested the true death toll could be as high as 1,300.

Syrian state media accused rebel forces of using chemical agents, saying some government soldiers had suffocated as a result during fighting.

After days of delay, the Syrian government finally offered yesterday to allow a team of UN inspectors access to the area. However, Mr Hague suggested that this offer of access four days after the attack had come too late....

Any retaliatory attack would be likely to be launched from the sea as the Syrian air force is judged to be strong enough to shoot down enemy jets.

A Royal Navy nuclear-powered submarine is said to be in the region while a number of warships recently left Britain for exercises in the Mediterranean.

Commanders may also need to make use of the RAF base at Akrotiri, Cyprus for air support.

If military action is approved, the first wave of missiles could start within a week.

Military sources suggested the early hours of the 2011 campaign against Col Muammar Gaddafi could form a template for any operation. The Libya campaign began with a blitz of Tomahawk cruise missiles from US warships and from a British Trafalgar Class submarine....