Grant Shapps, one of British Prime Minister Rishi Sunak’s staunchest Cabinet allies, was named U.K. defense secretary on Thursday as Sunak began a Cabinet reshuffle ahead of a general election that is expected to take place next year.

The move came after Ben Wallace formally submitted his resignation earlier in the day, honoring a promise made last month. Wallace was defense secretary for four years, overseeing Britain’s military response to the war in Ukraine.

Shapps, who supported Sunak during his campaign to become Conservative Party leader and prime minister last year, has been a Cabinet member since 2019, most recently serving as secretary of state for the Department of Energy Security and Net Zero.

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Wallace used his resignation letter to press for increased funding for the military, long his primary issue.

"I genuinely believe that over the next decade the world will get more insecure and more unstable,’’ Wallace wrote in his letter to Sunak. "We both share the belief that now is the time to invest. Ever since I joined the army, I have dedicated myself to serving my country. That dedication, however, comes at a personal toll to me and my family."

Grant Shapps

Grant Shapps leaves Downing Street after being appointed Defense Secretary following Ben Wallace's formal resignation in London on Aug. 31, 2023.  (Yui Mok/PA via AP)

Shapps is known as a gifted communicator, a key attribute ahead of what is likely to be a bruising general election campaign. But he has no experience in the fraught and complicated world of defense, which the ongoing conflict in Ukraine has complicated.

"As I get to work at @DefenceHQ I am looking forward to working with the brave men and women of our Armed Forces who defend our nation’s security, ‘’ Shapps said, adding he would continue "the UK’s support for Ukraine in their fight against (Vladimir) Putin’s barbaric invasion."

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Shapps visited Kyiv last week, visiting a power plant undergoing repairs following a Russian bombing.

The visit was billed as part of government actions to back supplies of fuel for Ukraine’s nuclear power plants. Shapps pledged a 192 million pound ($243 million) loan guarantee to help power Ukraine through the winter and to end its reliance on Russian supplies.

Replacing Shapps as energy secretary is Claire Coutinho, who was elected to Parliament in 2019 and most recently served as minister for children, families and well-being. A low-profile figure, Coutinho is also considered a staunch Sunak loyalist.

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The energy post is seen as a critical job since escalating fuel and utility costs arising from the war in Ukraine has aggravated a cost of living crisis that is causing the suffering of many.

"The new energy secretary’s inbox is already groaning under the weight of vital decisions which need to be made to reform Britain’s broken energy system,'' Simon Francis, coordinator of the End Fuel Poverty Coalition said. "Energy bills remain at record levels with every unit of energy costing double what it did in winter 2020/21, with daily standing charges also increasing and customers in record levels of energy debt.''