‘Oh yeah.’”

A man comes out of Paolo’s fish and chip shop. His van is parked on a double yellow line. When he sees Sean, his face falls. “Is that it then?” he asks. “I was only two minutes.” Sean replies: “How long can you park on a double yellow line? No time.”

But Sean does not issue a ticket. The driver says thank you as he pulls away. He was saved by the fact that Sean hadn’t started writing a ticket, and because there was a passenger, who Sean had been about to speak to. “It’s always best practice to give a passenger the opportunity to find the driver, or move the vehicle if safe to do so, though there’s no legal obligation to do this,” he says.

“There’s a big myth about us hiding on street corners, targets, and all the rest of it. Some of the practices people say we do, we’d do a lot better in terms of issuing tickets if we did them.”

Council traffic wardens are sometimes tarred with the same brush as private operators. An investigation has been launched in Cardiff after a private company’s warden was caught putting up a temporary ‘no parking’ sign before issuing a ticket. He then took the sign away and the car’s owner was sent a £100 penalty notice.

Sean used to work for UKPC, a company which patrols many car parks. “Every ticket after 25 tickets, I got £5 for. That’s not how parking should be.”

He says that despite the daily abuse, wardens receive more support than criticism. “The feedback we get around here is, we don’t come often enough. They’re right - we don’t. If we had the manpower to be here more often we would be.” Right on cue, a man drives past and shouts “Ticket them all, mate! They’re an absolute nuisance around here.”

A car is parked on double yellows outside a Chinese takeaway. Sean enters the details into his handheld device and has started printing a ticket when the driver emerges from the takeaway. “I’m very sorry - I was only a minute,” he says.

Sean isn’t for turning. “I’m going to issue this because it’s parked dangerously,” he says. The car is next to a junction, blocking the view of any driver pulling out of a nearby street. The man continues to plead, until Sean places the ticket on his windscreen.

The transformation is abrupt. The man scowls and utters an obscene insult. As he drives away he shouts another one. “We tend to get that if they can’t talk you round,” says Sean. Women tend to be the worst. They give you the eye. You say ‘I’m still giving you a ticket.’ Then it’s ‘You’re a .........’.”

Further down Denton Street a young woman returns to the car with the out-of-date blue badge. She raises no objection to the ticket on the windscreen. “It’s my mother’s,” she says of the badge. Allan’s instinct was correct. Sean takes a photo of the badge and asks her to send it back to the issuing authority. He will report the misuse.

Even though there are double yellow lines at the junction of Denton Street and Nelson Street, cars often park on this corner and restrict visibility for drivers and pedestrians. Tonight, with Sean and Allan patrolling for the past hour, the lines are clear.

A woman says to them: “I wish you could be here every night. It’s bliss. You can cross the road without being killed. My kids can come to the shop. When you come around here normally you take your life in your hands.”

There are other friendly interactions. I see Sean and Allan give parking discs to drivers who ask for them. All wardens are first aid-trained and have helped people who have fallen or been taken ill.

“Sometimes the job can be quite rewarding,” says Allan. “I’ve been quite lucky. In 10 years I’ve been punched once.”

It must be strange to know you could be attacked, verbally or physically, for doing a job which stops parking becoming a free for all in which vehicles are strewn across every junction.

Something Sean said earlier rings very true: “You get a sense that everybody wants parking enforcement but nobody wants to be subject to it.”