A senior UK central bank official sounded a warning note on the booming British house sales market on Thursday. In a speech to the Worshipful Company of International Bankers in London, Sir John Cunliffe, the Bank of England (BOE) deputy governor for financial stability, said average house prices had grown 10 percent in the past year to reach levels last seen in late 2006. The BOE is responsible through its Financial Policy Committee (FPC) with identifying and managing threats to financial stability and safeguarding the financial system. Cunliffe said, "Whether and how to act further if, following the pause of the last couple of months, momentum continues to build (in the housing market), will be the most challenging judgement the BOE Financial Policy Committee (FPC) will have to take in the coming months." Cunliffe said the FPC's response would depend on the nature of the risks to stability. The growth in house prices is being driven by several forces including relatively cheap credit, with the Bank Rate at a historic low of 0.5 percent and rising consumer confidence which may have unleashed pent-up demand, said Cunliffe. He said that there had been 3 million fewer house sale transactions 2008-12 as a result of the financial crisis than would normally be expected. "Many house purchases are linked to life cycle changes," he said, and many of these lost transactions may have "only been delayed until credit conditions and confidence about the future improved." Cunliffe said it was not implausible that this pent-up demand could significantly add to pressure on the market for the next few years.