His role was revealed by many news articles from the BBC. He received the role when he happened to pick up Britt Allcroft and her crew in his Taxi. According to Allcroft, after hearing him utter a few words, she told her colleagues "I have just heard the voice of Thomas. The man is exactly how Thomas would sound!". She offered John the part and he accepted it.
Speaking of his good fortune at the time to BBC News, "It's fantastic. I'm a bit shelI-shocked and have to keep pinching myself to remind myself that it has really happened." He continued: "All the lads at work have been really supportive, all the management have been really supportive and they are all going round singing Thomas The Tank Engine tunes." John was flown out to Toronto to record his lines along with Keith Scott, Michael Angelis and Patrick Breen.
However John was cut after American test audiences complained of his Liverpudlian tones making Thomas sound too old. In a statement following the decision in April 2000, Mr Bellis said he was "gutted", but wished the film-makers well. "It was supposed to be my big break," he said. "But it hasn't put me off and I am hoping something else will come along."
John was replaced by Edward Glen in the final cut. He is still credited in the movie as transportation co-ordinator.