Sir Alex Ferguson has confirmed he will not challenge his dismissal at Bolton last week. The Manchester United manager was sent to the stands by referee Mark Clattenburg at the Reebok Stadium, which centred around Ferguson's belief that the official had allowed Bolton to get away with far too many unfair challenges. One tackle by Kevin Davies on Patrice Evra infuriated Ferguson, prompting a finger-jabbing rant as Clattenburg entered the tunnel at half-time. Ferguson spent the second period in the directors' box alongside United's legal advisor Maurice Watkins and was duly charged by the Football Association with using 'abusive and insulting words towards a match official'. United have been given until December 11 to respond but Ferguson will not bother. 'We will just accept it,' said the Scot, who may receive a fine or touchline ban. While Ferguson will now await his punishment he is unrepentant about his grievance over Clattenburg's performance, adding that refereeing standards were 'slipping' within the English game. Although the Scot openly admitted he had not attended a pre-season briefing for managers by referees' chief Keith Hackett, he believes one of the central components of the discussion has been blatantly ignored. 'At the summer conference, Keith Hackett was on about tackling from behind,' he said. 'He made a promise to the managers that tackles with raised feet off the ground would be a red card and that tackles from the back would be a red card. 'Standards must be slipping because there have been some bad tackles recently, not just in our games but in quite a few others. 'And what happens then is that if someone gets seriously injured? Who gets the blame? The referee gets the blame.'