Britain's finance minister, Philip Hammond, scored the recent performance of the country's economy at "eight out of 10" on Monday, buoyed by high employment and strong growth but he said it also faced long-term challenges."On the data we have seen for the first half of this year this economy is running at eight out of 10 with high employment, strong growth, robust fundamentals," he told Sky News television on the sidelines of the Conservative Party conference."Of course we've got long-term challenges. We still have a poor productivity performance compared to many of our competitors and we run a huge balance of payments deficit ... so these are things we have to address." Hammond also said the country was going into the process of leaving the European Union at a time of global uncertainty.