Rivalry between Qatar and Saudi Arabia has fuelled wrangling within the Syrian opposition that threatens to prevent a united rebel delegation attending international peace talks next week.

Sources in the Syrian National Coalition and diplomats from foreign powers backing the rebels said it remains unclear whether those divisions can be overcome by Friday, when the 120-member Coalition is expected to vote on whether to take part in the conference in Switzerland known as Geneva-2.

However, some expect that Qatar, which raised its profile in diplomacy by being quick to back the Arab Spring revolts, will not in the end risk angering Riyadh, Turkey and Western states by having Doha’s allies on the Coalition force a boycott of talks that are supported by the other powers.