David Cameron is being considered for an international role as the next Nato secretary-general, according to reports.

The former prime minister is reportedly believed to be the most likely British candidate if Theresa May wants to appoint a Briton to Europe's top defence job, which comes with a tax-free salary of €260,624 (£222,390).

The current head of Nato, former Norwegian prime minister Jens Stoltenberg, will finish his term in either 2018 or 2019.

May's advisers believe Britain's best chances of securing leadership of Nato for the fourth time in history would be to put forward an ex-prime minister, the Daily Mail reported.

The newspaper quoted an unnamed government source who said that "more recently former prime ministers have won out over foreign or defence ministers".

Cameron's allies in government are said to be keen on him taking the top job, believing Britain would benefit from his return to the world stage.

"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," one senior member of May's Cabinet told the Daily Mail.

Friends of Cameron, who resigned as PM in June after failing to convince the public to vote against Brexit in the EU referendum, said it was crucial for the UK to get the Nato job if it wants to fulfill the government's aim of playing a greater role in European security.

One said: "[It will] show EU allies that we want to play a constructive post-Brexit role on the continent."

They added: "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."

Nato is said to view Britain as a strong contender for the role, with its military strength in the 28-country alliance second only to the United States.

The top diplomatic job is traditionally filled by a senior statesman from a European Nato member country, with member states putting forward candidates before a decision is taken behind closed doors by consensus.

The role as Nato's top general, the Supreme Allied Commander, is always filled by an American.

Stoltenberg started his four-year term in 2014, with Nato members due to choose whether to extend it by a year or replace him in 2018.

Should Cameron become Britain's candidate as his successor, his first hurdle will be to gain the support of the alliance's most powerful member, the United States.

During the US presidential election campaign Donald Trump questioned whether he would come to the aid of Nato countries that failed to meet defence spending obligations of 2% of national income.

Britain is one of only five Nato members on target to meet their spending commitments.

It has held the position of Nato secretary-general three times, with Lord Ismay serving from 1952 to 1957, then Lord Carrington from 1984 to 1988 and finally Lord Robertson from 1999 to 2003.

A spokesman for the former prime minister declined to comment.