DAMASCUS. Bolstering Syria’s moderate opposition is crucial to excluding extremists from power in the war-gripped country, the UK’s foreign secretary has said.William Hague was speaking as Arab and Western foreign ministers gathered for talks with Syrian opposition officials.The London talks are trying to lay the groundwork for planned peace negotiations in Geneva next month.But a key group in Syria’s main opposition alliance is threatening to boycott the meeting dubbed Geneva II.The Syrian National Council (SNC) has been unwilling to talk to representatives of Bashar al-Assad’s government.Ministers will say unity is vital among the fractured groups of Syria’s armed and political opposition if peace talks are to have any chance of success.Rebel rivalriesIn London, foreign ministers from 11 countries - the so-called Friends of Syria group - are trying to encourage opposition groups "to have a united position” ahead of Geneva II, Mr Hague told the BBC’s Today programme. Mr Hague admitted that an increasingly prominent role was being played in Syria by Islamist rebels linked to al-Qaeda, who are engaged in no kind of peace process and who have been involved in bitter struggles with more moderate forces."The reason we have to make sure we are supporting and dealing with the moderate opposition committed to a democratic, pluralistic, non-sectarian future for Syria is precisely because if they don’t have a role, then all the Syrian people have got left is a choice between Assad and extremists,” Mr Hague said."The longer this conflict goes on, the more sectarian it becomes. That’s why we’re making a renewed effort” with Geneva II, Mr Hague said.At Tuesday’s talks, Britain, Egypt, France, Germany, Jordan, Italy, Qatar, Saudi Arabia, Turkey, the United Arab Emirates and the United States are expected to reaffirm their view that Geneva II must be about a political transition in Syria away from the Assad regime.