Hidden disabilities include conditions such as dementia, autism, learning disabilities, anxiety issues, mental health impairments and hearing loss, according to the CAA, which set out guidance for airports to improve the way they help these passengers three years ago.

Now, Virgin Atlantic has introduced its own Hidden Disabilities programme, which includes the creation of a bookmark, photo symbol and badge for a passport to alert employees to those passengers needing assistance. Airline staff have also been given training.

Other initiatives include the airline’s passenger accessibility team working with individual passengers before the flight to help them, such as arranging for them to be escorted through the airport or being given priority boarding and reserved seating when necessary.

The airline will also take measures such as ensuring that in-flight entertainment system is provided for blind passengers, with cabin crew also trained in sign language for deaf and hard-of-hearing customers.

Geraldine Lundy, Virgin Atlantic’s passenger accessibility manager, said: “We are committed to giving all customers easier access to travel.

“The Hidden Disabilities scheme is one of a series of initiatives that Virgin Atlantic is planning on introducing over the coming years to help those with disabilities overcome any key challenges they may face.”

To launch the programme, Virgin worked with Tom Morgan, from the TV programme The Undateables, who suffers from Tourette’s, Asperger’s and attention deficit hyperactivity disorder (ADHD) and travelled with Virgin on his first long-haul flight with his girlfriend.

“Geraldine and her team go above and beyond to ensure that your flight experience is tailored to your specific needs,” explained Morgan.

“For instance, I asked if I could be sat at the back of the plane so that if I was to experience ticks on the flight, I wouldn’t disturb the passenger behind me.

"Virgin Atlantic easily accommodated my request, which made me much less nervous about the flying process.”

Virgin said research showed 20% of those who fly have a disability, and 70% of these people have a hidden disability.

Sara Marchant, Gatwick’s accessibility manager, added: “It is so important to cater to the needs of all customers, including those with hidden disabilities.

"This sector has been all too easily overlooked in the past and so it is fantastic that the airline is targeting those whose conditions are not so apparent.

"We are keen to support this impactful initiative.”