Keir Starmer has announced a major shake-up of his political team, including the departure of his chief of staff, Sam White, saying Labour is now on an election footing. Boosted by turmoil in the Conservative party and a string of hefty leads in opinion polls, Starmer said the party needed to move into the next phase of election readiness. In a call with party staff, Starmer said: “We are turning the page to the final act of opposition: driving the Labour party into government. It’s going to get harder as we get closer. But imagine how good it’s going to feel when we complete it. We can achieve what people said was unachievable.” Labour HQ will now oversee key parts of the party operation including communications and policy development in order to hone its messaging and manifesto offer. No further jobs are expected to be lost. The shake-up is a major shift in approach from the Labour leader’s office, which has seen internal splits over its direction. White, whose departure had been rumoured in Labour circles for some time, was among those blamed for excessive caution seen as hindering Starmer’s approach. White, who joined the leader’s office last year having previously been a Treasury special adviser under the former chancellor Alistair Darling, will depart on amicable terms, Labour said. In a statement, White said the role of chief of staff to the leader was likely to shrink as attention turned to the election campaign. “The next phase of the campaign needs a different structure, but we part very much as friends with the intent to work together again in the future,” he said. “You’ll find no greater champion for a Starmer government than me. Britain needs a Labour government and Keir will be the outstanding prime minister we deserve.” White is not expected to be immediately replaced and a Labour source said the priority for the new role would be leading on transition to government work as well as day-to-day management. The shake-up will hand significantly more power to senior figures in Labour HQ such as campaign director Morgan McSweeney, a close ally of Starmer. He will be joined by Marianna McFadden as his deputy, currently at the Tony Blair Institute and another veteran of the previous Labour government. “Anyone who has worked with Marianna knows she isn’t just a brilliant organiser but also has really sharp political antennae. She will bring a discipline to decision making that will ensure everyone is on the same page and knows what they are supposed to be doing and saying,” one former colleague said. A number of key figures in the shadow cabinet and inside the leader’s office have been making the argument that the party needs to be more nimble and politically opportunistic. “This is a major victory for our wing, it shows Keir is really up for the fight and that the party cannot be complacent,” one senior ally said. In the call with staff, Starmer said the party had a newfound confidence and a belief that victory was within reach. “The government’s collapse has given us a huge chance. The instability means they could fall at any time. Because of that, we need to get on an election footing straight away.” But he said that despite polls showing leads of up to 33 points, the party could not be “complacent or cautious” – caution being a criticism of his operation over the past year. He said the changes to the party structure “will move us on to that election footing. We’ve been planning this for a while but the scale of the Tory collapse has brought it forward.” Starmer said White “leaves behind a powerful legacy … A great deal of what’s been achieved over the last year wouldn’t have happened without him. I want to thank him for his frank advice, unstinting loyalty and all his support to me during some challenging times.” He said the role in the leaders’ office would become “a smaller role than Sam signed up for and we both agree as we’re making this change, now is the right time to go. I hope we’ll work together again in the future.”