Hamid Karzai, Afghanistans president, extended his lead over his main challenger in the nations presidential election on Saturday as Gordon Brown made a surprise visit to UK troops deployed in the south of the country. The latest batch of results from last weeks election gave Mr Karzai 46.2 per cent of the vote compared to 31.4 per cent for Abdullah Abdullah, his former foreign minister, based on results from 35 per cent of polling stations. The tally put Mr Karzai closer to obtaining the 50 per cent needed to avoid a run-off with Mr Abdullah, although the count could still change significantly as the rest of the votes are tallied. Final official results are not due to be released until late next month, after a commission to set up to investigate allegations of fraud has processed hundreds of complaints. Mr Abdullah has accused the government of presiding over massive state-engineered rigging in the vote, marred by an extremely low turnout in the south and allegations of ballot-stuffing and intimidation. Mr Abdullahs sympathisers have also been accused of electoral abuses. Facing mounting criticism at home over his conduct of the war, the British prime minister visited a military base in Helmand Province, where growing casualties among UK troops have helped make this the deadliest year for international forces in Afghanistan. The death toll for British soldiers killed in Afghanistan stands at 207. Reports that turnout was very low in areas secured at the cost of British soldiers lives has fuelled a wider debate in the UK over the conduct of the war. Mr Browns government has faced months of allegations that it has failed to provide enough troops or equipment to support forces engaged in heavy fighting with Taliban insurgents. Scenes of the bodies of British troops returning in flag-draped coffins shown repeatedly on British television in recent weeks have pushed Afghanistan higher up the political agenda ahead of general elections, which must be held by June next year and which Mr Brown is widely expected to lose. Mr Brown said UK forces were being supplied with equipment to protect them from deadly roadside bombs and called for faster efforts to train Afghan security services to allow them to play a bigger role in pushing back the Taliban. Ive talked to Mr Karzai and Mr Abdullah and Ive made it absolutely clear to them that we expect over the next year that they will train and we will work with them to do so around 50,000 more Afghan forces, Reuters quoted Brown as telling reporters at Camp Bastion, Britains main military base in Afghanistan. He did not comment on the election. With four months of 2009 still left to go, this year has already become the deadliest yet for international forces deployed in Afghanistan since the Taliban government was toppled in 2001. Total fatalities among all forces in the Nato mission have already crept above the total of 294 who lost their lives in the whole of 2008.