Credit rating agency Moody's has lowered Britain's credit outlook to 'negative' from 'stable' in the wake of the country voting to leave the European Union.Following the Brexit vote, it said Britain's economic growth will be weaker and warned the public finances will be weaker than previously forecast, meaning it will be harder to cut the deficit. A negative outlook means there is a greater danger of a country being downgraded. It is three years since Moody's cut Britain's AAA rating.