BORIS Johnson's idea for a new brightly coloured "Brexit plane" to help him sell Global Britain abroad has 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 insisted it was not aware of "any plans for the current transport situation to change".

He also pointed out 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, we probably do need something.

"The taxpayers won't want us to have some luxurious new plane but it's striking that we don't seem to have access to such a thing at the moment," added Mr Johnson.

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 on the grounds of cost by his successor Gordon Brown.