By Tamara Cohen and Matt Chorley PUBLISHED: 04:06 EST, 21 December 2012 | UPDATED: 12:38 EST, 21 December 2012 Former Chief Whip has lost confidence in the head of the Met Police in the growing row over the investigation into his stand-off with Downing Street officers David Cameron is under growing pressure about why he failed to publicly challenge the police over the plebgate affair when doubts about the police's account emerged three months ago. Downing Street identified inconsistencies between claims Chief Whip Andrew Mitchell called police 'f****** plebs' in a row in September, but was reluctant to question Scotland Yard's account.
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Prime Minister says he had doubts about claims against his Chief Whip three months ago
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Andrew Mitchell lets it be known he has 'no confidence' in Scotland Yard chief Bernard Hogan Howe
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Police Federation admits mistakes in stoking 'pleb' row
Mr @placeholder resigned from government a month after ranting at police officers who told him he could not ride his bike through the gates of Downing Street.