Every living Prime Minister who has quit politics will be called to give evidence in public to a major new anti-corruption lobbying inquiry to be announced on Monday. The investigation by MPs on the Public Administration and Constitutional Affairs committee (PACAC) will be the biggest and most wide ranging public ‘show trial’ into the lobbying of officials and ministers. On Saturday, William Wragg, the chairman of the committee, likened the new investigation (which will hear all evidence in public and is expected to report by the end of July) to a probe by the fictional police anti-corruption unit ‘AC-12’ on the BBC’s hit TV series Line of Duty. Mr Wragg said: "PACAC may not be the AC12 of Whitehall, nor do we envisage encountering anything quite as exciting as in a television drama. "However, it is at least a sense of duty that motivates our work, just as duty and service motivates the vast majority of those in public life. As ever, we must not let the questionable judgement of a few tarnish all." Several other inquiries have been launched into the scandal which started when it emerged that former Prime Minister David Cameron had texted government ministers in a bid to save Greensill Capital, in which he had a major financial stake, from collapse.