Boris Johnson is being backed by senior Tories to be the next secretary general of Nato when the high-profile role next becomes free.
The Prime Minister is being touted as a candidate to fill the key defence post, with the incumbent Jens Stoltenberg widely expected to stand down in September next year.
Mr Johnson is the latest British politician to be tipped for the role, after Ben Wallace, the Defence Secretary, and Theresa May and David Cameron, both former prime ministers.
The timing of the role would allow Mr Johnson some time to recharge his batteries after he stands down as Prime Minister on September 6.
He would need to quit as an MP to take up the role, which is appointed unanimously by Nato member countries.
A British candidate has long been tipped for the role because of US distrust around any European Union figures taking the job, given repeated suggestions of plans for a new EU army.
Britain is also trusted by the Baltic states, and Mr Johnson personally has won international credit for helping to build the international coalition against Russia's Vladimir Putin.
Richard Drax MP, a senior Conservative member of the defence select committee, said he would support the Prime Minister for the role if he wanted it.
Mr Drax told The Telegraph: "Any distinguished Brit would be a great choice. If indeed that is what Boris Johnson wants to go and do, of course, I would support that."
Mark Francois MP, another member of the defence committee, added: "People will probably argue over Boris Johnson's legacy for years – but one thing which is clearly inarguable is his absolutely staunch support for Ukraine in the face of Russian barbarity.
"If he were to apply to become the Secretary General of Nato, I suspect he could rely on President Zelenskyy for a reference."
David Jones, the former Brexit minister, added: "Boris has actually led the Western response to Putin. It was Boris who went to Sweden and Finland and urged the leaders of both countries to make applications for Nato membership, which of course they did."
However, there was concern among the top brass, with Lord Dannatt, former head of the British Army, saying that he could not support Mr Johnson because of his character.
The peer told The Telegraph: "Undoubtedly he has done a lot of good things and our full square support for Ukraine is fantastic.
"But I am afraid it is the personal stuff, the lack of integrity, the lack of trust. Frankly, we don't want to expose Boris Johnson on the international stage for more ridicule. He is a national embarrassment."
A senior Ministry of Defence figure also expressed doubts, given there was a likelihood that Emmanuel Macron, the French President, would veto him.
One source told The Telegraph: "The reality is that Nato sec-gens are appointed by unanimous decision. Any country can veto.
"Do you think President Macron would nominate Boris Johnson to be the sec-gen of Nato? It is a challenge for a Brit fullstop. You need the United States to support you and the French to say 'yes'."
The next head of Nato was due to be appointed this September but was delayed by a year due to the crisis in Ukraine.
The last UK politician to become Nato secretary general, one of the world's most senior defence appointments, was Lord Robertson of Port Ellen – who at the time was Labour Defence Secretary – in 1999.
'He understands the challenges'
Oleksiy Goncharenko, a Ukrainian MP, was at the forefront of calls for Mr Johnson to take up the post when present Secretary General Jens Stoltenberg steps down next year.
Mr Goncharenko said: "Boris Johnson's leadership during this war has ensured vital military, economic and humanitarian supplies have been provided to Ukraine.
"The UK has been one of our most important supporters and has imposed meaningful sanctions on Russia.
"He would be the right person to take over from Jens Stoltenberg as he understands the challenges that Nato and the West face.
"He will always support Ukraine in our fight against the 21st century's Hitler, and will support Nato members and Nato goals with the same level of unstinting support."
Number 10 declined to comment.