When Sue Gray went from being a backroom Whitehall fixer to household name because of her Partygate report, the senior civil servant was so uncomfortable at being thrust into the limelight that she privately joked to colleagues last year she had seriously considered changing her name by deed poll. Now Gray occupies an even bigger role in frontline politics. No longer an impartial official advising ministers, she shocked Westminster by jumping ship to take up a political post as Keir Starmer’s chief of staff. After honouring a six-month break between jobs – ordered by the Whitehall revolving-door watchdog – Gray began her new role this week, and immediately got stuck in. Her first day was Monday, when MPs traipsed back from summer recess and Starmer overhauled his top team. While insiders said the tone and shape meant it was very much “Keir’s reshuffle”, they detected – if not her hand in, then her approval of – certain decisions, such as appointing Hilary Benn as the shadow secretary of state for Northern Ireland, where Gray worked in the 1980s, as a pub landlady. Labour media aides were keen to capitalise on her arrival. They invited one of Westminster’s most prolific photographers, Stefan Rousseau of the Press Association, up to her office to take some pictures. Gray posed with two green chairs bearing portcullis symbols, before taking to the balcony for some more photos. But one cabinet minister said afterwards: “I think that was a mistake. They’re effectively saying ‘she’s part of the story’ and it will make her more of a political target.” Gray was introduced to Labour HQ staff on Tuesday, which was described as a big morale boost. As well as the polite clapping after Starmer spoke, there was even said to be “whooping and hollering”. She assured the more than 100 staffers assembled: “I will have your back.” Her warmth was said to have gone down particularly well with more junior members of the office. Others tuned in on Teams, including staffers already out canvassing before the forthcoming byelections. Keen to be a visible presence in the office, afterwards Gray, Starmer and David Evans, the party’s general secretary, took the time to walk around Labour headquarters and talk to all the staff and different teams about their role. “She was asking questions and listening to thoughts and ideas,” said one. Gray also sat in on the first meeting of the new shadow cabinet. On Wednesday, the most high-profile moment of the week in Westminster took place – prime minister’s questions. Preparation for both Rishi Sunak and the leader of the opposition is always crucial. That morning, Gray was part of the cadre of aides that gathered for the final prep session. Insiders said her instincts would prove invaluable at helping skewer Sunak across the dispatch box. She continued to go down well in meetings with other advisers. “When you start a new job there will always be a certain amount of platitudinous nonsense,” said one source. “But she was impressive, and when asked questions was happy to come down on one side and answer.” Gray was clear in speeches to her new colleagues throughout the week that there was a lot of work to do. She will get a honeymoon period, but her real test will come closer to the election. There still remains a clear division of responsibilities in the leader of the opposition’s office. Morgan McSweeney, Labour’s campaign director, will remain in charge this side of the election. If Labour wins, as polls suggest, Gray will take over the reins in government. As Gray is a former civil servant, those working with her are keen to see “how much political fire there is in her belly”. One ally of Starmer’s also cautioned: “I think everyone expects Sue will be the answer to all their problems. She will inevitably have to disappoint some people.”