A Downing Street spokesperson said:
The Prime Minister spoke to President Hollande this morning about the situation in Syria.
In a telephone call this morning, the Prime Minister and President Hollande reiterated their strong condemnation of the attack that took place in Damascus on Wednesday. They agreed that the failure of the regime to grant UN investigators immediate access to the area was extremely worrying and demonstrated that the regime was hiding the facts and evidence.
They agreed that a chemical weapons attack against the Syrian people on the scale that was emerging demanded a firm response from the international community. This crime must not be swept under the carpet. They agreed to keep in touch in the days ahead.
Read more: Syria chemical weapons attack