Sutton Coldfield MP Andrew Mitchell is facing more calls to quit today, after being accused of calling No 10 police officers "plebs".
The former shadow police minister is alleged to have shouted "learn your f****** place" when he was stopped from cycling out of Downing Street's main gates.
Although the MP, the government's chief whip, has apologised for not treating officers with due respect, he has denied using some of the language reported.
Metropolitan Police Federation chairman John Tully told ITV News that Mr Mitchell was "lucky not to have been arrested".
Yesterday (21 September), David Cameron dodged questions about whether he planned to sack Mr Mitchell and condemned his behaviour as "wrong" and "inappropriate".
Mr Mitchell, who was also a minister under John Major in the early 1990s, apologised by telephone to a police officer.
Senior Tory backbencher David Ruffley defended his colleague.