An airline has apologised for serving wine to a toddler on a flight to London.

The flight attendant is said to have handed the three-year-old boy a glass of sparkling white when dinner was being dished out in business class

He gulped down the clear liquid after tucking into his chicken, only to grimace as the acidic drink overwhelmed his young palate.

The boy's shocked mother, Mrs Wong, 35, said she only realised the beverage was alcoholic when the boy complained about the 'sour' taste.

She angrily called over the cabin crew to demand an explanation before lodging an official complaint with Hong Kong flag carrier Cathay Pacific.

Mrs Wong said she was racked with fear about her boy's health following his accidental binge on the 14-hour flight. A French passenger even tried to calm her down by explaining it was normal for children on the continent to drink.

Cathay Pacific eventually made a statement apologising for the blunder onboard the Boeing 777 on flight CX255 from Hong Kong to London Heathrow on April 24.

The angry mother said: 'The flight attendant started to serve dinner to passengers, and our child just had chicken and water. We saw a glass of a water-like drink served to him, and then my husband went to his seat and cut the chicken for him.

'My husband went back to his seat. But after a while, my son asked for water again, and then we asked what the problem was, he said he took a sip and the water was too sour. We immediately took a sip and found it was white wine instead of water.'

The furious parent alerted a flight attendant, who apologised and swapped the wine with water. However, Mrs Wong said she was dissatisfied with the 'indifferent response', and yelled for another senior flight attendant to demand medical attention.

She added: 'What made us most angry was that during this process, the first thing the attendant did was to ask for our e-mail to open a complaint for me. What I wanted was a doctor. They didn't take our child's life or death seriously at all.'

The staff sought medical advice through the in-flight service Medlink, while a French doctor onboard, citing cultural norms in France where children are allowed to drink small amounts, assured the panic-stricken Mrs Wong that a sip of wine was no cause for alarm.

Mrs Wong said she endured a 'really painful' 14 hours, constantly checking on her son for any adverse effects. She added she was unable to sleep well because she 'almost lost her child's life'.

The family deboarded the flight, but said they remained worried despite no immediate medical symptoms manifesting.

In an email on April 26, Cathay Pacific apologised to the irate mother.

The statement read: 'We take this matter extremely seriously. It is our responsibility to ensure that all passenger requests are handled with care and accuracy, especially where the safety and comfort of young passengers are concerned. We deeply regret that this standard was not met in this instance.'

The airline said immediate coaching and briefing sessions were held with relevant cabin crew members following the incident.

Cathay Pacific also offered three one-class upgrade vouchers, a full refund of the boy's ticket, and vowed to shoulder any related medical expenses.

However, Mrs Wong said she wanted a 'proper explanation' of the incident, and will proceed with filing complaints with Hong Kong's Tobacco and Alcohol Control Office, the Hong Kong Civil Aviation Department, the Consumer Council, and the UK Civil Aviation Authority.

In a post on Chinese social media, she continued to blast the carrier, saying: 'As the fifth largest airline in the world, Cathay Pacific has no official issues after such a serious accident. It is really disappointing. We are filing a complaint and are willing to share the facts with different media outlets. We will continue to keep you updated.'

A Cathay flight purser has blamed the mix-up on allegedly rushed hiring and training practices to fill staff shortages post-pandemic.

A spokesman for the Cathay Pacific Airways Flight Attendants Union said Cathay was still conducting investigations to prevent a repeat of the incident.