The family cannot get a refund - and has not been told why it could not travel to the country
A Labour MP has called on the Prime Minister to intervene after a British Muslim family were stopped at Gatwick Airport and prevented from flying to California.
The group of 11, including nine children, was about to travel to Los Angeles on a dream holiday last Tuesday when they were approached by US Homeland Security officials in the departure lounge.
The officials told Mohammad Tariq Mahmood and his party, which included his brother and nine of their children aged between eight and 19, that their authorisation to travel on the flight had been cancelled without further explanation.
Labour's Stella Creasy, who is the family's local MP, has written to David Cameron to try to find out why the family were stopped.
She also said a growing number of British Muslims claim they have received similar treatment.
Ajmal Masroor, an imam in east London, told Sky News he was also banned from flying to the US last week, something he described as "crazy" and an "insult".
Mr Masroor had been invited to lead Friday prayers at a mosque in New York. But when he arrived at the gate to board his flight, he was told by someone who said they were a US official that his visa had been revoked.
Mr Masroor said: "He would not give me any reason, he said he was only a messenger.
"But when I questioned him a bit more, he said 'maybe you've done something wrong, you need to speak to the embassy.'
"I was very furious he would make accusations against me without any proof or any substantial evidence that he could provide me and they would arbitrarily refuse or revoke a visa."
A week on from the cancellation of their flight, Mr Mahmood said they still had not been given a reason.
But he told The Guardian: "It's because of the attacks on America - they think every Muslim poses a threat."
The family have also reportedly been told by their airline, Norwegian Air, that the £9,000 cost of their flights will not be refunded.
Ms Creasy believes a lack of information from US authorities about why they were prevented from travelling is fuelling resentment within British Muslim communities.
The claims come after Republican presidential hopeful Donald Trump recently called for all Muslims to be stopped from entering the United States.
Ms Creasy said: "It is not just the family themselves who are livid.
"The vacuum created by a refusal to provide any context for these decisions is fuelling resentment and debate.
"Online and offline discussions reverberate with the growing fear UK Muslims are being 'trumped' - that widespread condemnation of Donald Trump’s call for no Muslim to be allowed into America contrasts with what is going on in practice."
She also said there has been no further contact from either the UK or US security services to follow up any potential threat the family were perceived to be.
The family, from her Walthamstow constituency in northeast London, had applied for and were granted travel authorisation online a number of weeks before their flight.
Mr Mahmood said the children had been excited about the trip for months, and were devastated not to be able to visit their cousins in California and go to Disneyland and Universal Studios, as planned.
Ms Creasy has hit a "brick wall" in her own inquiries and has asked Mr Cameron to press US officials for an explanation as to why the Mahmoods were prevented from flying.
A Downing Street spokesman said: "The Prime Minister would consider the issues raised and respond in due course."
Sky News has asked the Home Office to comment.
Norwegian Air said in a statement: "We can confirm that a group of passengers were denied the right to board a flight from London Gatwick to Los Angeles on Tuesday at the request of the US Department of Homeland Security.
"Norwegian fully complies with requests from the border controls of each country we serve."