The family of the teenager being held in Dubai over a holiday romance with a 17-year-old girl last night declared trying to free the teenager was a huge 'emotional battle'.
Marcus Fakana was arrested for having a sexual relationship with the unnamed girl while they were on holiday in the UAE.
He has been detained there awaiting trial early next month.
In a new statement, his family said: 'We are praying for the day we can be returned with Marcus.'
His parents said: 'We've sought assistance from Foreign secretary David Lammy to ensure his right to upheld and we ask HH Sheikh Mohammed Al Maktoum, the ruler of Dubai, to please let our boy come home.
'This ordeal has caused us terrible emotional and financial strain and every day is an emotional battle.'
The boy's family, who are from Tottenham, North London, said they were grateful for the continued support from the public, the media and friends and family who 'have been incredible and gives us hope'.
More than £24,000 has been raised to help the legal fight to return Marcus to Britain, but the family warned that a fake go fund me page was also in existence.
The family of Marcus Fakana, from Tottenham, London, say his mental health is 'deteriorating' as he is stuck in Dubai facing the possibility of up to 20 years in a Dubai jail
Marcus pictured with his family, who are hoping to raise £20,000 to help toward his legal fees
Marcus was held in Dubai's 'notorious' Al Barsha Police Station for days after the 'strict' mother of the girl he had sex with on holiday this summer reported him to authorities.
The couple, who had met while staying at the same hotel with their families, 'had a wonderful time together', with the girl - also a Brit - meeting up in secret as she feared she could not tell her mother she was seeing a boy.
But in a devastating turn of events, Marcus - who had been on a family holiday celebrating his father's birthday - could face two decades inside a gruelling UAE prison after the girl's furious mother found out about the fling and informed police in Dubai upon returning back to the UK.
While the relationship would have been legal in the UK, under Dubai law a 17-year-old is defined as a child. The girl has since turned 18.
Setting up a GoFundMe page to raise money for legal fees to bring him home, Marcus' family said: 'What was meant to be a happy time has turned into a nightmare for him, our family, and our friends.
'This has happened as a result of someone trying to misuse UAE law against him.
'He is being charged with a crime that could lead to imprisonment for up to 20 years.
'He is only 18 years old, very scared, and his mental health is starting to decline.'
Dubai has only recently reformed its laws on sex outside of marriage for tourists, but upholds a strict Islamic legal system, and has no firm ruling on age of consent.
But under local law, a child is defined as a person under 18 years of age. The girl was just months away from turning 18 when the pair met in August.
The 18-year-old was detained in a notorious Dubai police station after the mother of a then 17-year-old girl he had a holiday romance with reported him to authorities
The teenagers were planning to continue their relationship when they were back in London.
But it is understood the mother had found out about their relationship when she went through her daughter's phone and found their chats and pictures, later sharing them with Dubai police from the safety of the UK.
The lawyer's fees alone could cost them up to £21,000.
In a previous GoFundMe page set up two months ago, the family alleged Marcus had been denied a translator and forced to sign a confession document he did not understand.
They said: 'He has been wrongfully accused of a crime he did not commit, and is now caught in a legal battle in Dubai.
'This is not just a misunderstanding, it is racial discrimination, with someone seeking to use the UAE law against him.
'While detained he was denied access to a translator and forced to sign a confession document he didn't understand. He is only 18 years old, terrified, and very scared.
'His mental health is deteriorating rapidly.'
Speaking to British-based aid organisation Detained in Dubai, Marcus told of how the couple had planned to see each other when they got home.
Marcus said: 'We had a wonderful time together. We really liked each other but she was secretive with her family because they were strict.
'My parents knew about our relationship but she couldn't tell hers. She had to meet me without telling them it was to see a boy.
'When she left, I couldn't wait to see her again when I got home. Then suddenly, police knocked on our hotel door.
'They said they were taking me in for questioning but wouldn't tell me why. I couldn't imagine what for. I was frightened and my parents were terrified.'
The pair had tried to spend as much time as they could together while abroad, and hoped to get to know each other better when back in London.
The girl left Dubai first and they had arranged to meet up.
'He [Marcus] was told his girlfriend's mother had reported the relationship to authorities in Dubai after she had arrived back in London,' said Radha Stirling, CEO of Detained in Dubai and human rights advocate.
While the relationship would have been legal in the UK, under Dubai law a 17-year-old is defined as a child. The girl has since turned 18
Marcus' parents have asked Dubai ruler HH Sheikh Mohammed Al Maktoum 'to please let our boy come home'
The Mail on Sunday revealed last week that Foreign Secretary David Lammy (pictured) had finally acted on desperate pleas to aid Marcus
The organisation offers confidential legal help to people facing civil and criminal legal trouble in the UAE.
'This is clearly a very strict mother to involve police in a private matter that is completely legal in the country where she lives and where the children have grown up,' Ms Stirling warned.
'Perhaps she wasn't aware that she triggered the possibility of a young man of only 18 spending the next 20 years in prison.'
'My mother is a cleaner and my dad works in a warehouse. They saved up for this one-off holiday and they have now used all of their savings,' Marcus explained.
'The police demanded 10,000 AED for bail which I've been told is not normal and the costs are mounting. I'm here all alone. I pray this nightmare will be over and I'll be home for Christmas.'
Marcus and his family are now calling on the British Foreign Secretary to help him.
'Dubai police have the power to drop the case against Marcus and let him come home,' Ms Stirling said.
'This is not something we want to do to young people and we ask David Lammy MP to convey this message to his counterparts in the UAE.'
The UAE has only recently implemented changes allowing tourists to have sex outside of marriage - as well as more lax regulations on alcohol and vaping.
A British couple were jailed for kissing in public in 2010, and ultimately deported for violating the country's decency laws.
Despite changes to the law, Ms Stirling warns that parents will soon 'be scared to take their older teenagers on vacation with them where they could end up losing their lives over behaviour that's completely legal in their own countries'.
Dubai Public Prosecution said in a statement shared with MailOnline: 'The case was initiated in response to a complaint filed by the mother of a 17-year-old British girl.
'The girl, a tourist visiting Dubai, is not a resident of the UAE. Under UAE law, the girl is legally classified as a minor, and in accordance with procedures recognised internationally, her mother -being the legal guardian- filed the complaint.
'Dubai's legal system is committed to protecting the rights of all individuals and ensuring impartial judicial proceedings. The next court hearing has been scheduled for 9 December at the request of the defendant's legal counsel, contrary to what has been reported by some media.
'The media should avoid speculation and allow the judiciary to carry out its responsibilities within its clear legal framework.'