A Downing Street spokesperson said:
The Prime Minister spoke to Prime Minister Rudd this morning to discuss how the international community should respond to the chemical weapons attack in Syria last week.
They agreed that it was increasingly certain that the regime was responsible for the attack, particularly since the regime had refused to give the UN immediate access to the site, which demonstrated that they had something to hide.
They reiterated the need for a serious response to this attack from the international community. The world cannot stand idly by in light of such a significant chemical weapons attack. They agreed to keep in touch over the coming days.
Read more: Syria chemical weapons attack