An international conference on Syria this week will do little to help resolve the crisis and the delay is dragging the country closer to full-scale civil war, an opposition figurehead warned Wednesday.

Prominent writer Louai Hussein, president of the Building the Syrian State movement, said political progress on ending the bloodshed had stalled, and international efforts had been hamstrung by Russia and China.

BSS representatives are on a visit to London, where they said they will meet Middle East minister Alistair Burt.

"The violence is escalating very quickly, especially in areas like Homs," Hussein told reporters at The Arab British Centre.

"On the political track, it's stuck, there is no progress at all.

"The international community is being very active, but we see it developing into a more polarised position," he said, citing Russia and China's veto of a UN Security Council resolution.

Tunisia is hosting a "Friends of Syria" conference on Friday in a bid to bring an end to the Damascus regime's bloody repression of protests. Arab, European and US diplomats are set to take part.

Hussein, one of the first political figures arrested in the current uprising, said the conference was not preparing for a solution to the crisis; "it's preparing for more pressure on the regime. At best, it can offer humanitarian aid to people outside the country.

"We haven't seen anybody putting forward a feasible solution to the crisis, and this is very serious for Syria.

"If the situation is left like this, this is certainly going to lead to a civil war -- a stage where we will all lose control of what happens in Syria."

He called for negotiations on establishing a power-sharing transitional government, involving President Bashar al-Assad's regime.

"We believe that the beginning of the solution should be mutual agreement on sharing power in Syria," he said.

He said Moscow and Beijing were responsible for turning the Syrian crisis into an international one.

"Now we have an increased polarisation. This divide is going to lead to a similar one within Syrian society and increase the divisions. This is why we think the international interference in this way is making it more difficult to solve."