The Foreign Secretary has defended chartering a private jet to Australia after reports estimated the journey would have cost taxpayers around £500,000.

Critics said the move was a “grotesque misuse” of public money, but Liz Truss said the Government plane was available “precisely so that Government ministers can travel”.

The Independent reported the Foreign Secretary had opted for the chartered flight for her trip last week due to security concerns, although commercial routes were available.

The newspaper said she had travelled on the private government Airbus A321, which a senior source told them would have cost £500,000 to operate.

Ms Truss, asked about the reports, told broadcasters during a trip to Northern Ireland: “I used the Government plane – that is why we have a Government plane: to enable Government ministers to conduct Government business, and that’s what I flew to Australia in.”

Pressed on whether it would have been better to have used commercial flights instead, the Cabinet minister said: “Every Government decision is based on value for money.

“We have a Government plane specifically so ministers, like me in my role as Foreign Secretary, can go and do the work overseas, which is ultimately delivering for the British people.”

The Foreign Office said the trip was within the rules set by the ministerial code.

Liz Truss said private planes were available to ministers embarking on overseas tripsLiz Truss said private planes were available to ministers embarking on overseas trips (Aaron Chown/PA)

Officials said using the private jet allowed the trip’s delegation to travel together and have private discussions on sensitive security matters, that commercial flights were fully booked, and that using a commercial flight would have separated Ms Truss from her delegation and protection team.

It also gave Ms Truss the option of returning to the UK early if needed, it is understood.

Labour’s deputy leader Angela Rayner, however, said the decision to fly privately showed the public “exactly quite how little respect this Conservative Government has for taxpayers’ money”.

She said: “It is obscene that Government ministers are jet-setting yet are hiking taxes and refusing to do anything to help working families when they are feeling the pinch of the cost of living crisis.

“Tories waste disgusting amounts of public money on their own vanity and comfort, Labour wants to see families see a cut to energy bills, that is the difference.”

SNP environment spokeswoman Deidre Brock criticised Ms Truss’s mode of travel, saying it was a “grotesque misuse of taxpayers’ money to fund her jet-set lifestyle”.

She said: “With a record like this, Lavish Liz will make a fitting successor to Boris Johnson.”

In a policy paper called Back to Black which Ms Truss co-authored in 2009 she, along with others, outlined how public sector workers should take care with what they spend, starting by “travelling by economy rather than business class”.

The ministerial code says ministers can authorise non-scheduled flights “when a scheduled service is not available, or when it is essential to travel by air, but the requirements of official or Parliamentary business or security considerations preclude the journey being made by a scheduled service”.

Chris Bryant, Labour chairman of the Commons Committee on Standards,  tweeted: “For comparison, my first trip as a foreign office minister was on easyJet at 6am and we didn’t pay for speedy boarding.”

A Foreign Office spokesman said: “It’s necessary for the Foreign Secretary to travel abroad to pursue UK interests around security, trade and technology, as she did during this visit to Australia.

“Travelling this way allows ministers to have private discussions on sensitive security matters and flexibility to respond to rapidly changing global events.

“This trip used Government transport and was fully within rules.”

The plane Ms Truss used for her trip was recently given a makeover, according to photographs shared online last year.

It was painted in the colours of the British flag, much like a larger private aircraft available to ministers, RAF Voyager, which in 2020 was controversially given a new paint job costing almost £1 million.

The contract for the Airbus A321 said it “must be operated in a ‘Global Britain’ livery”, with an included stipulation saying it can only be used by the Government.