Abdelbaset Sieda, the head of the Syrian National Council, told a meeting of Syrian opposition representatives and diplomats, that a deal similar to the post-Second World War European reconstruction effort, known as the Marshall Plan, would be needed in the event of the fall of the Assad regime.
He said Assad has devastated the public finances and institutions to such an extent the country will not be able to rely immediately on oil revenues and taxes in any rebuilding effort.
The gathering of a working group on economic rebuilding, which Germany chairs jointly with the United Arab Emirates, is designed to address how to prevent basic services and infrastructure collapsing, and how to revive the economy in a post-Assad Syria.
“In the aftermath of the destruction ... we are convinced Syria needs a Marshall-style plan to ensure it stands again on solid financial and economic ground,” Mr Sieda said. “Without real comprehensive development we will open up the opportunity for the growth of all kinds of extremism in the region,” he said.
Unlike neighbouring Iraq, Syria lacks vast oil reserves that could kick-start the economy and help finance the reconstruction.
Syria used to produce about 380,000 barrels of oil a day, of which 250,000 were for local consumption and 130,000 for exports. By comparison, oil giant Saudi Arabia produces about 10 million barrels a day.
Diplomatic efforts to solve the seemingly intractable conflict in Syria have failed so far, but western nations say preparations need to be made for a post-Assad future.
Violence has been escalating in recent weeks and the Syrian Observatory for Human Rights and the Local Co-ordination Committees have raised their total death toll to between 23,000 and 26,000. Activists say 5,000 people were killed in August, the highest toll in the 17-month-old uprising and more than three times the monthly average.