The Commissioner of the Met Police is calling for mandatory drug-testing for all workers. Sir Bernard Hogan-Howe says anyone failing the test and refusing to get help, should face the sack. The full story now from Richard Pallot.
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The high of 35C was recorded on a Bakerloo line train between Piccadilly Circus and Oxford Circus at 2pm.
Weather forecasters say temperatures could reach 35C, beating the previous record of 34.6C in the scorching summer of 1976.
After years of political manoeuvring over the future expansion of Heathrow Airport, there has been an important development this lunchtime.