The appointment comes as the Duke and Duchess of Sussex continue to face criticism over their use of private jets

Prince Harry's eco-travel firm Travalyst has appointed Graham Miller as its new director, a figure who has previously compared frequent flyers to drink-drivers.

The appointment comes despite the Duke of Sussex and Meghan Markle facing repeated accusations of hypocrisy over their use of private jets since Travalyst was launched in 2019.

Harry, 41, established Travalyst seven years ago with the stated aim of making the tourism industry more sustainable.

Yet almost immediately, he and the Duchess of Sussex found themselves branded hypocrites after taking four private jet journeys within just 11 days that same year.

The younger son of King Charles sought to deflect the criticism, insisting that "no one is perfect" and that "we can all do better."

He also cited security concerns as justification, stating: "Occasionally there needs to be an opportunity based on a unique circumstance to ensure that my family are safe."

Mr Miller made his views on flying culture clear during his time as a lecturer at the University of Surrey.

"There was a time when mentioning on a Monday that you'd just flown back from Milan or New York made you sound sophisticated.

"Now it's like boasting that you drank five pints and drove home," he remarked in 2020.

His new employer, meanwhile, had struck a different tone. In July 2019, the duke declared that "every choice, every footprint, every action makes a difference."

Weeks later, however, Harry attracted criticism for taking a private jet to visit Sir Elton John at his home in Nice.

The pattern of private jet travel persisted well beyond 2019. In 2022, Harry addressed the United Nations, warning that climate change was "wreaking havoc on our planet."

Yet the following year brought fresh scrutiny when the couple took a 40-minute flight from a private airstrip close to their California home to see Katy Perry perform in Las Vegas.

Their 2023 travels also included a 2,000-mile journey aboard a Falcon 7X from New Jersey to the exclusive Caribbean island of Canouan for a holiday, before continuing in the same aircraft to Atlanta, Georgia.