Grant Shapps has been announced as the UK’s new defence secretary, as the prime minister carries out a mini-reshuffle at the top of government.

The appointment comes after Ben Wallace revealed last month he would be leaving the role the next time Rishi Sunak made changes to his cabinet – as well as stepping down as an MP at the next election.

Mr Shapps had been serving as the energy security and net zero secretary before his promotion to the Ministry of Defence.

Politics live: Mini-reshuffle begins – follow live updates

The new role will be his fifth cabinet position in a year – having been transport secretary under Boris Johnson, having a brief stint as home secretary under Liz Truss, and having been appointed business secretary when Mr Sunak first took office.

It is not yet clear who will replace Mr Shapps in his current role, but minister for children, Claire Coutinho, was seen entering Number 10 this morning.

Sky News’ deputy political editor Sam Coates said both MPs were “loyalists”, adding they had been chosen “not just perhaps because of their skills, but because they have stuck by Rishi Sunak”.

Tweeting after his appointment, the new defence secretary said he was “honoured to be appointed” to his post and he paid tribute to his predecessor’s “enormous contribution… to UK defence and global security”.

Mr Shapps added: “As I get to work… I am looking forward to working with the brave men and women of our Armed Forces who defend our nation’s security. And continuing the UK’s support for Ukraine in their fight against Putin’s barbaric invasion.”

But the new hire has already attracted criticism from opposition parties, with Liberal Democrat defence spokesperson Richard Foord saying: “At a time when the Armed Forces need someone to stand up for them, Rishi Sunak has appointed a yes-man.

“The Conservative government merry-go-round has to stop. They have taken the Armed Forces for granted for too long, and we are all left less safe as a result.”

Labour’s shadow defence secretary John Healey congratulated his new opposite number on Twitter – but accompanied his welcome with a dig.

“The first duty of any government is to keep our country safe and I will always work with the new defence secretary on this basis, especially on Ukraine.

“But after 13 years of Tory defence failures, a change at the top will not change this record.”

‘Time to invest’

Mr Wallace officially resigned his post on Thursday morning, saying it had been a “privilege” to serve in the post for four years.

In his letter to the PM, he said the Ministry of Defence was now “more modern, better funded and more confident than the organisation I took over in 2019”, and it was “back on the path to being once again world class with world class people”.

And in a parting shot to secure his department’s future, Mr Wallace added: “I know you agree with me that we must not return to the days where defence was viewed as a discretionary spend by government and savings were achieved by hollowing out.

“I genuinely believe that over the next decade the world will get more insecure and more unstable. We both share the belief that now is the time to invest.”

Mr Sunak responded to the letter by saying the outgoing defence secretary had “served our country with distinction”.

He added: “I fully understand your desire to step down after eight years of exacting ministerial duties. As you say, the jobs you have done have required you to be available on a continuous basis.

“But I know you have more to offer public life both here and internationally. You leave office with my thanks and respect.”

A Labour source said Mr Wallace had “shown important leadership in supporting Ukraine from the start”.

But, while they said the former minister “deserves credit for his support” of Ukrainian fighters, “his record on British armed forces has been poor, with cuts and procurement failures the order of the day”.

The source added: “The new defence secretary needs to get a grip, boost British forces and give them the resources, kit and accommodation they deserve.”

Former prime minister Boris Johnson said he was “sad to see the departure” of Mr Wallace, who “got so many calls right – especially on Ukraine”. But he praised the expected appointment of Mr Shapps, calling it “an excellent choice”.