Sir Graham Brady, whose role as chair of the Conservative party’s 1922 Committee saw him usher three prime ministers out of Downing Street in four years, is to step down as an MP at the next election. The most powerful backbencher of his political generation, Brady released a statement to his local newspaper saying it was time to “bring this fascinating and fulfilling chapter of my life to a close”. Brady, the MP for Altrincham and Sale West in Greater Manchester since the constituency was created in 1997, has never held ministerial office but has chaired the committee that represents Tory backbenchers since 2010. During that time he observed four prime ministerial departures – David Cameron, Theresa May, Boris Johnson and Liz Truss – and subsequent elections for a successor, and in three of the cases played a pivotal role in their resignations. As chair of the 1922 Committee, Brady is the custodian of any Tory MPs’ letters of no confidence in the prime minister, and if 15% of their contingent submit one, a confidence vote is held. As the letters mounted against the four prime ministers, Brady would be pursued around Westminster by TV crews asking for a running tally, which he would never divulge, responding only with inscrutable bonhomie. With May, it was Brady’s duty to tell the prime minister that if she did not announce a timetable for her departure in 2019, he would amend party rules to allow a second confidence vote, after she won an initial challenge. While Johnson was primarily pushed out by a mass of ministerial resignations, a pivotal moment came when Brady arrived at Downing Street to tell the prime minister, who had also won a confidence vote, that if he did not depart he would inevitably face another, and lose. Just a few months later, in October last year, the end of Truss’s brief and chaotic time in No 10 was heralded when Brady arrived to once again pass on the verdict of the backbenches. Within two hours, Truss was gone. In his statement, Brady said colleagues had “given me the unique opportunity of chairing the 1922 Committee for longer than anyone else in its 100-year history”, and that he would remain in the role until the end of the parliament if they wanted him to. “I will continue to do everything I can to support the Conservative cause and Rishi Sunak,” Brady said. “He is bringing both stability and vision as prime minister. “I have decided to bring this fascinating and fulfilling chapter of my life to a close while I am young enough to pursue other opportunities and interests, so I will not be standing at the next election.” Now 55, Brady held some junior shadow frontbench roles before taking the helm at the 1922 Committee. One aspect of his decision to stand down could be the shrinking majority in his always slightly marginal seat, now less than half of the 13,000 margin at its peak in 2015.