The safety of Tony Blair MP (Prime Minister) is being investigated after a security breach in the grounds of Downing Street. A man armed with a large kitchen knife scaled a six foot high fence and jumped into the so-called secure zone behind Number 10. He was immediately pinned to the ground by a police protection officer and is now being questioned by detectives. Blair was at home, but police insist neither he nor his family were in danger. A full review of security has already begun.