Burhan Ghalioun, the leader of the Syrian National Council, and Haytham Manna of the National Co-ordination Body for Democratic Change in Syria, signed the draft on Friday. The UN says more than 5,000 people have been killed by government forces since the revolt began in March.

The agreement says the groups reject any foreign military intervention, and stipulates that, as soon as Mr Assad goes, a “transitional period” will begin by preserving all state institutions, before a constitution is drafted to guarantee a “civilian pluralist parliamentary democratic system”. Then a parliament and president will be elected. The draft also calls for “liberating Syrian territory”, an apparent reference to the Golan Heights occupied by Israel since 1967.

Scores of Arab League monitors were in the country last week to ensure the regime complies with terms of league’s plan to end Mr Assad’s crackdown on dissent. Despite the observers’ presence, regime forces killed at least 27 people on Friday.