BORIS Johnson has been branded a “trash act” after it was revealed a military plane used by the Prime Minister and members of the royal family is being repainted in the colours of the Union flag.

The grey RAF Voyager jet is receiving a pre-planned makeover at an airport in Cambridge, with red, white and blue expected to be used.

Sky News reported a defence source saying the paint job sounded like something "from Austin Powers". They added: "Boris doesn't like it being grey. He is getting it painted up.”

In 2018, Johnson publicly questioned why the plane is grey, and said as foreign secretary that he would like to have a "Brexit plane" to help him travel the world and promote the Government's vision of global Britain.

He complained that the RAF Voyager jet, which is shared by the Prime Minister, senior Cabinet members and the royal family, "never seems to be available".

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An RAF source told the PA news agency that speculation that such a plane would have an "appropriate paint scheme based on the Union flag would not be incorrect".

A source also told the Daily Mail: “It’s going to be a Voyager with a paint job. Boris and others will use it to go around the world and wave the British flag.”

They denied that the plane will be “a flying Union Jack”, stating: “It won't be the whole of the airplane, it will be a part of it.”

A spokesman for the Royal Air Force said: "An RAF Voyager is currently in Cambridgeshire for pre-planned works."

SNP defence spokesperson Stewart McDonald, citing the PM’s U-turn on school meals vouchers in England, condemned the decision.

He tweeted: “Boris Johnson put more thought into this than he put into kids going hungry over summer. He really is a trash act.”

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The MP added: “There are serving members of the armed forces having to buy their own pieces of personal kit & uniform. Some staying in housing you wouldn’t put a dangerous dog into, waiting months for basic repairs. Pay and conditions deteriorating. But sure, the PM must have his toys painted.”

Scottish Constitution Secretary Michael Russell suggested the Prime Minister should reconsider his priorities. He posted: “Brexit priorities ... blue passports and now red white and blue aircraft ... even at this time … Boris Johnson's jet gets 'Union Jack makeover'”.

Number 10 has been approached for comment.