British Airways passenger Andrew Wilkinson said he was forced to endure a flight to South Africa while sitting in someone else’s urine.
The 39-year-old IT consultant paid £1,242 for the return business class flight in July.
When he realised the seat was damp, he claims the air hostess gave him wet wipes to clean it up himself.
Mr Wilkinson said: “I called the stewardess who agreed the dampness was urine.
“She went to the toilet and came back with some wipes and expected me to clean up the mess myself.
“I told her: ‘I can’t sit here’ but she just laughed. Her response was: ‘I can see you are going to work me really hard on this flight, aren’t you?’
“In the end, I put a plastic bag over the seat and covered it with a blanket.”
Mr Wilkinson tweeted about his experience after the flight, which prompted BA to initially offer him 5,000 Avios points.
The airline also offered him a £435 flight voucher or upgrade on his next journey to Cape Town.
He said: “I am not bothered about compensation. I’d just like a proper apology.
“The one they sent me was clearly a general response.”
British Airways said the flight Mr Wilkinson was travelling on was completely full so there were no other seats for him to be transferred to.
A spokesperson said: “We were very concerned to hear about this and have been in touch with our customer to apologise and make amends.