Labour says to hold British EU vote only if more powers move to Brussels

LONDON (Reuters) - A future Labour government would only hold a referendum on Britain's membership of the European Union if more powers were transferred to Brussels, party leader Ed Miliband will say Wednesday. Prime Minister David Cameron has promised to try to reach a new settlement with the EU before holding an in/out referendum by the end of 2017, provided he wins the 2015 election. Miliband's pledge means that if Labour wins power in 2015 there is little prospect of a referendum on Britain's EU membership at least until 2020. "I am announcing that the next Labour government will legislate for a new lock: there would be no transfer of powers from the UK to the EU without a referendum on our continued membership of the EU," Miliband wrote in the Financial Times. "It is important to emphasise that there are no current proposals - from either the EU or any member state - for a further transfer of powers from Britain," he said. Miliband will say Labour believes Britain's future is in the EU, but that the block should do more to address economic challenges and voter anxiety over immigration. Cameron said Miliband's comments showed that only the Conservative party could guarantee and deliver on an EU referendum. "By his own admission, Ed Miliband says it's unlikely there'll be an in-out referendum on Europe under Labour," Cameron said in a statement on Twitter. (Reporting by Ana Nicolaci da Costa; editing by Guy Faulconbridge)