Air Transat customers who were trapped for six hours on a sweltering hot plane in Rome are speaking out about what they describe as dismal conditions.

More than 300 passengers sat in the plane for hours as temperatures tipped 30 degrees Celsius in the Italian capital. Some travellers said the airline didn’t provide enough food and water, with one flyer comparing the ordeal to a hostage situation.

Brian Costa, who was on the flight bound for Toronto, described the harrowing conditions at Leonardo da Vinci International Airport to CTV News Channel.

“It was a pretty horrific experience,” he said.

“I wouldn’t want anybody to go through that experience, especially considering the cabin was probably 40 plus degrees.

“They did open up two doors, but unfortunately, I guess the design of the plane, it didn’t really circulate any air.“

Costa said it was “survival of the fittest” to get snacks and there was limited water as tensions grew among the frustrated passengers.

Following a number of delays, Air Transat eventually cancelled the flight due to a lack of crew.

“There was a severe lack of communication on Monday (July 29) when we were supposed to leave,” Costa told CTV News Channel.

“The following day a new captain was very clear about what was going on and how long things would take. Mind you, there was still a two-hour delay more or less on the second day.”

Because the delay was in Europe, passengers were entitled to around $900 in compensation.

European Union rules stipulate that airlines must pay 600 euros to passengers for delays of four hours or more on long-distance flights. Hotel accommodation was also provided.

Costa said he was also offered a $1,100 Air Transat voucher to be used within 18 months. He chose the cash.

“The 600 euros or $900 is something they are required to pay because of the delay, it doesn’t speak to the conditions in which we were held, and I’m going to use this term loosely, hostage, ” Costa added.

“It doesn’t seem justified and it’s inhumane. You wouldn’t leave a dog in a hot car, what about people in a hot plane?”

Air Transat confirmed to CTVNews.ca that flight TS309, scheduled to operate between Rome and Toronto with 336 passengers on board, departed at 1:46 p.m. local time on Tuesday July 30, after a delay of 23 hours and 46 minutes.

This delay was initially caused by a mechanical problem, the airline said.

“However, some passengers expressed their desire to leave the aircraft,” Air Transat spokeswoman Debbie Cabana told CTVNews.ca.

“The deployment of logistics to carry out this disembarkation took some time and did also cause additional delay for the passengers who were still on board.

“Since our flight crew is subject to government regulations regarding crew fatigue management, the combined time delays no longer allowed our crew to fly. We had to take the decision to postpone the departure of our flight to the next morning.”

Air Transat said it regretted the inconvenience caused.

“We have done our best to ensure their (passengers) comfort by providing snacks and water, activating the air conditioning system as soon as possible and communicating regularly,” Cabana said.

The incident comes on the heels of new federal air passenger rights protections in Canada, which came into effect last month.

In the event of a tarmac delay, aircraft must return to the gate after no more than three hours and 45 minutes. Passengers must have access to washrooms, heating or cooling, food and water, and communication with people outside the plane free of charge, "if feasible," the Canadian Transportation Agency (CTA) said.

Compensation of up to $1,000 for delays of nine hours or more will not take effect until December.

Passenger rights advocates say the rules do not go far enough, arguing the CTA's criteria for monetary compensation exempt situations that are defined as "outside of the airline's control."

--- With files from The Canadian Press