By Samuel Indyk LONDON (Reuters) -Britain’s pound fell to its lowest level in over a week against the euro after data showed a sharp slowdown in business activity, adding to concerns that the UK could slip into recession later this year. S&P Global’s flash Composite Purchasing Managers’ Index (PMI), a monthly gauge of the services and manufacturing industries, fell to 51.8 in May from 57.6 in April, its lowest level since February last year. The preliminary reading was worse than all forecasts in a Reuters poll of economists, which had pointed to a drop to 57.0. “This sudden deterioration in g…