Boris Johnson’s idea for a new brightly coloured “Brexit plane” to help him sell Global Britain abroad appears to have failed to get off the ground.

Speaking on an official tour of Latin America the Foreign Secretary had said the RAF Voyager jet shared by the Prime Minister, senior Cabinet members and the royal family “never seems to be available”.

He also suggested its drab grey colour scheme undermined its impact as a travelling symbol of Britain.

But a Downing Street source on Wednesday said that it was not aware of “any plans for the current transport situation to change”.

They also pointed out that the grey colour scheme was because the aircraft, a military adaptation of an Airbus A330, was still used “operationally to do important things like refuelling”, as the Foreign Secretary was aware.

Mr Johnson is conducting his current five-day tour of Latin America by commercial flights, taking a variety of airlines as he hops from Peru to Argentina and Chile with an entourage of officials and press.

He had to stop off in Madrid to change planes on his Air Europa service from London to Lima, adding five hours to the journey time, because the only direct flight on offer did not fit his schedule.

But he insisted it was not his own comfort he was concerned about, using an arcane term for staying overnight as he joked: “We are hard as nails, we Foreign Office types. We don’t care about changing planes, we pernoctate on planes.”

Asked if he would like to have a “Brexit plane”, he told reporters: “If there’s a way of doing it that is not exorbitantly expensive then yes I think we probably do need something.

“The taxpayers won’t want us to have some luxurious new plane, but I certainly think it’s striking that we don’t seem to have access to such a thing at the moment.”

The Foreign Office currently has use of the Queen’s Flight fleet of BAE 146 jets, one of which Mr Johnson used to fly to Moscow before Christmas.

He described the 26-seater planes as “superb… masterpieces of engineering”, but said they were coming up to 40 years old.

NATO Summit in Brussels
The RAF Voyager used by the Prime Minister and other VIPs is never available, according to Boris Johnson (Steve Parsons/PA)

Tony Blair’s plans for a prime ministerial jet – branded “Blair Force One” for its similarity to the US president’s private airliner – were dumped by Gordon Brown as a cost-saving measure.

The Voyager began its work transporting VIPs in 2016, after a £10 million refit under David Cameron.

But he took only one flight on it before handing over to Theresa May, whose travels have earned it the nickname of the “ThereasyJet”.

In order to keep costs down, it was announced the 58-seater plane would continue conducting air-to-air refuelling missions for the RAF when not in VIP use, and retain its military livery.

Mr Johnson revealed its multiple users mean it is difficult for senior ministers to book when they need it, saying: “What I will say about the Voyager, I think it’s great, but it seems to be very difficult to get hold of.

“It never seems to be available. I don’t know who uses it, but it never seems to be available.”

And he added: “Also, why does it have to be grey?”

Boris Johnson Latin America tour
The Foreign Secretary has travelled on a variety of modes of transport during his trip to South America, including commercial airline, helicopter and boat (Stefan Rousseau/PA)

Responding to the Foreign Secretary’s comments, the Prime Minister’s official spokesman said: “There are flights available for ministers when they need them.

“The Voyager has been used on occasions when ministers have been carrying out business on behalf of the Prime Minister.”