The Commissioner of the Metropolitan Police is calling for mandatory drug-testing at work.
Sir Bernard Hogan-Howe says that anyone failing a drug test and refusing to get help should face the sack.
He wants it to cover all occupations, but the special focus would be on teachers, transport staff and health staff working in intensive care.
The law says workers must consent to being tested, but can face disciplinary action in certain circumstances if they refuse.
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The Boxing Day sales got off to a flying start with shops reporting a surge in business during the first hour of trading.
Bus strikes are planned for Monday 29 December and Monday 5 January.