Lucy, 39, from Swindon in Wiltshire, told BBC the Passport Office initially refused the application for Khaleesi, six.

Khaleesi is the name of actor Emilia Clarke's character Daenerys Targaryen in the popular show.

The officials said they could not issue her passport since it needed Warner Brothers' permission as the company owned a trademark over the name.

"I was absolutely devastated, we were so looking forward to our first holiday together," Lucy told BBC.

Lucy said she had saved and planned for her dream vacation to Disneyland Paris before applying for her daughter's passport.

"But then I had a letter come through from the Passport Office, saying her name is trademarked by Warner Brothers," she told BBC.

"It was the first I've heard of such a thing - I was astonished," she said.

She was left with no other choice but to consult a legal advisor who said the trademark was applicable for goods and services but not for the name of a person.

"That information was sent to the Passport Office who said I would need a letter from Warner Brothers to confirm my daughter is able to use that name," she said.

Meanwhile, a passport official called Lucy to apologise for the issue.

An Official explained there had been a misunderstanding and the guidance staff had originally given applies only to people changing their names, reported BBC.

Lucy said the official informed her daughter's passport could be processed.

The mother is hopeful of visiting Disneyland Paris in future.

A Home Office spokesperson told BBC: “We can confirm the application is being processed and apologise to the family for the delay.”