Christopher Rodrigues, Chairman from VisitBritain:
Security is of course paramount, but it would be a tragedy if all the work being put in to showcase Britain around the Jubilee and the Olympics was undermined by a negative first impression as the world's press arrives to cover these events.
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The Football Association has announced it has received an offer to buy Wembley Stadium.
The most hotly-tipped date is July 13, following the Nato summit which the president is due to attend in Brussels on the previous days.
Abbas Edalat, a professor in computer science and maths at Imperial College London, has reportedly been held in custody since April 15.