The Equalizer film 2012 - who should play Robert McCall?

An action film of the 80's hit show The Equalizer is planned - but what actor would be good to play Robert McCall? Russell Crowe is interested, but I just can't see it. It would have to be a middle aged British actor but I just can't think of one. The late John Thaw would have been good and you can forget Midsomer Murders star John Nettles. Any ideas?