The senior leaders of the Welsh-language broadcaster will be replaced after a year-long crisis, after the chair said he would not stand for a second term. Rhodri Williams has written to the UK government asking not to be considered for the position as chair of S4C when his tenure runs out at the end of March, despite telling MPs last week that he thought he should remain in the job. It follows the sacking of the former chief executive Sian Doyle in November, after a report said she was “dictatorial, creating a culture of fear”. Doyle said she did not “recognise or accept the allegations” against her. Parliamentarians at Westminster and the Senedd had called for Lucy Frazer, the culture secretary, to find a replacement for Williams after a bullying scandal that culminated in the sacking of Doyle and another senior female executive. Last week Williams was accused by MPs during an evidence session of the Welsh affairs committee of acting as “judge, jury and executioner” in the sacking of the two women, before the committee’s chair, Stephen Crabb, wrote to Frazer expressing his concern about the chair’s ability to oversee the changes required and “given the importance of S4C and the scale of the challenges”. The crisis also put the culture secretary under pressure when it emerged in evidence sessions that she had not met the chair of taxpayer-funded S4C during the difficulties. Senedd politicians wrote to Frazer last Thursday to say they were “astonished” she had not met the chair despite repeated requests. S4C has been in turmoil since bullying allegations against Doyle were raised by the Bectu union in April last year. Her chief content officer, Llinos Griffin-Williams, had a bullying complaint about Williams upheld before being sacked for gross misconduct after an incident after a rugby match in Nantes, weeks before Doyle’s dismissal. Doyle told the Guardian that the manner of her dismissal demonstrated an “unprecedented lack of governance for a public body”. She wrote to Frazer calling on her to urgently investigate S4C and Williams. Griffin-Williams denied gross misconduct and the comments attributed to her, and said she had been dismissed without a fair investigation. Both women are understood to have commenced legal action against the broadcaster on multiple grounds. On Tuesday, Williams told S4C’s Newyddion programme that he was content with the way the board unanimously dealt with the situation. “I think it was right to appoint an external and independent company to investigate,” he said. “And after hearing from them, we had no choice [but to sack the former chief executive]. “I think the board and myself as chair have acted properly and in the interests of S4C staff and the establishment as a whole.” Williams hit back at the politicians who questioned him. “The focus wasn’t on the centre of this story, which, in my opinion, is how staff have been treated by the leadership,” he argued. “They are the people who should be scrutinised.” In a letter to the board of S4C, after Williams’ decision not to stand again for the role of chair, Frazer said: “There are lessons to learn, and it is vital that such reflection is incorporated into your plans moving forward”. Given “the scale of the challenge” she urged them to get external advice to strengthen the broadcaster’s culture and practices. The S4C board said that it was “working on a plan to ensure a successful future for S4C” and would update the culture secretary as soon as possible, adding: “Fostering and building an open, transparent, inclusive and forward-looking culture is our utmost priority.”