I have heard hundreds of descriptions of Brighton and Hove since I moved here but few as evocative as Tony Mernagh's.

"Brighton is like a shark," says the man responsible for getting people and businesses to concentrate on initiatives that make the city a better place to live, work and shop.

"A shark can't breathe because it has no way of pulling water across its gills - it has to keep moving forward. If it stops, it dies.

"This city is like that. Unless we keep moving forward, we're going to die."

I'm terrified but the city centre manager just thinks it makes things exciting. Then again, anyone who describes his five years in an El Salvador hit by civil war as just "very exciting" probably does not scare easily.

He trained as a biology and chemistry teacher in London after leaving Middlesbrough at the age of 17.

He taught in Surbiton for three years before he and his now wife decided they wanted something other than suburban bliss.

He says: "We wanted some excitement so we applied for a few jobs around the world. We weren't that bothered where we went.

"It just so happens El Salvador was the first place to offer work for both of us."

Within two months of them arriving, the killing of an archbishop had helped trigger the civil war.

Mr Mernagh says: "People were saying the country was a bit too hot for them and within six weeks we were, effectively, the only people left. We decided to stay and spent five years there.

"It was probably the best five years of my life."

The couple returned to England, intending to continue teaching abroad but Mr Mernagh's sister-in-law who lived in Brighton, made them an unexpected offer to go into business.

He says: "She thought Brighton needed a trendy, upmarket greetings card shop and asked us if we were interested in going into business together.

"We said okay. We had visited Brighton before and liked it but we only expected it to last six months because we had never been in business before.

"But this was 1984 when retail was booming."

The business was called Graffiti, which is ironic "because I now spend a lot of my time trying to combat the real thing."

He was always searching for a bigger challenge and this ambition, combined with five years' experience volunteering for the North Laine Traders' Association, got him the job of town centre manager in 1999 after the decision had been made to make the City Centre Business Forum a "proper" organisation.

He says: "I don't use my job title very often because it makes me sound like I'm the commissioner of Gotham City.

"People might imagine I have this bank of phones and I pick up one and say 'Get that done'. But it's not like that."

Instead, he "persuades or cajoles" people. He says: "The difficult part of the job is persuading the business community to engage.

"I tell them it's better to take the opportunity to contribute than ignore it and then, when a decision has been made, get annoyed about it.

"We're in an interesting and, in some ways, uncomfortable position at the moment. War seems inevitable and during the past week businesses down here have changed from being wary to wearily accepting we're heading for hard times."

However, he says Brighton has its own problems to resolve. He says: "The nation's problems affect us just like everywhere else but Brighton itself is entering a phase that is both exciting and important to its future.

"I think there is a conflict between the people who live here and the people who visit.

"You hear a lot of people saying 'We don't want these visitors clogging up our roads and pavements'.

"Unfortunately, that's what our economy is based on. "We don't make anything. We rely on people coming to Brighton to shop, chat or take short breaks. If those people stopped coming, this city would be in a very bad state.

"Many people who complain don't really understand the economics of the city and how many jobs depend on visitors.

"It's unfortunate everything you want to do here meets with such opposition."

One example he gives is the problem of providing affordable housing.

He says: "We have very little space but we have to have accommodation for the city's people and their children.

"Quite rightly, people don't want to concrete over the Downs so we're going to have higher densities and this almost certainly means building upwards.

"Yet anytime anyone suggests building something more than four storeys high, someone pops up to say 'no'."

Outside work he enjoys sculpting, which he started after his wife booked him on a night-school course.

He says: "One of the great things about the city of culture bid was people being paid to try things for the first time.

"That's what people need to hear - 'Try it and if you don't like it, forget it, it doesn't matter'.

"We've got five years to tackle some of the problems that are impeding the city's growth and because of the state of the economy, we're probably going to have less money to do the creative thinking we need.

"But it's so important we do it, do it properly and do it now."