In a statement to parliament, the Foreign Secretary said that there was increasing evidence that chemical weapons – in particular the nerve gas sarin – had been used by forces loyal to President Assad.
There is a growing body of limited but persuasive information showing that the regime used – and continues to use – chemical weapons," he said. "We have physiological samples from inside Syria which have shown the use of sarin, although it does not indicate the scale of that use. Our assessment is that chemical weapons use in Syria is very likely to have been by the regime."
He added that there was no evidence of use of such weapons by the rebel forces.