David Cameron has emerged as a frontrunner to be the next secretary general of NATO after reports he will be nominated by Theresa May.

The former prime minister is reportedly being lined up by the UK Government as a candidate to replace the current secretary general, former Norwegian prime minister Jens Stoltenberg, when he steps down in 2018 or 2019.

Michael Fallon, the Defence Secretary, has previously said the UK will play a bigger role in Nato to make up for its withdrawal from the EU.

Cabinet sources said they want to find a prominent role for Mr Cameron, who resigned in June after losing the EU referendum.

One senior Cabinet minister told the Daily Mail: “We’ve got to find a role for him – he has so much to offer. We have got to get him batting for Britain again.”

Allies of Mr Cameron suggested he would be interested in the role. One said: “The key at this stage is to flag high-level interest in leader level conversations and to show that our eventual candidate is visible and acceptable to everyone.

“That means a would-be candidate would need to start talking about the right issues and show up at various conferences such as the Munich Security Conference and Davos.”

Key to winning the position will be securing the support of the United States. The secretary general is appointed by consensus after discussions between the 28 Nato member states, but American support is seen as important in influencing other states.