The Metropolitan Police has told ITV News that 50 people have been temporarily detained as a result of the 'critical mass' procession.
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Under the new rule adults over the age of 18 automatically become donors after their death, unless they opt out beforehand.
Doctors have recommend Peter Sutcliffe be moved to high security prison, but the final decision will be taken by the justice secretary.
Last minute suspension of strike action has meant thousands of cancelled procedures will still not go ahead.