The plot so far: Mild-mannered architect Will Alsop hears cry of distress from northern city in fear of economic life – ducks into alley and emerges as The Regenerator. Armed only with carefully selected fruit and veg, he leaps into action …
He wants to turn Barnsley into a Tuscan hill town. He wants to put an enormous glass blob next to Three Graces on Liverpool's waterfront. And, most recently, he has formulated the idea of creating a 130-mile "supercity" stretching from Liverpool to Hull.

Will Alsop might not quite be the most famous architect in Britain today, but he is one of the most audacious, and the most active in urban regeneration. The architect's name is rapidly becoming linked with large-scale regeneration thanks to a series of high-profile masterplan commissions. As well as the Barnsley plan, put forward by regional development agency Yorkshire Forward, there is a commission to regenerate Bradford and Urban Splash's plan to reinvent 29 acres of east Manchester as "New Islington".

Despite this popularity with the clients, his approach has courted controversy. Some regeneration specialists see him as muscling in on a specialist area that requires hard-headed economic planning know-how, rather than blobs and stilts. Others are frustrated at the ease with which his fame and flamboyant style seem to get him the big jobs. What does the man himself say to all this?

To say it's too aspirational – that's the whole f***ing point!
Alsop may be regeneration's darling, but that hasn't given him an easy ride. Last year, Lewisham council in south London dispensed with the services of his firm, Alsop Architects, on the grounds that his framework for New Cross Gate was "more aspirational than achievable". The idea – to create a townwide school "campus" with the music department doubling as a nightclub and the maths department used as a tax advice centre – was certainly visionary.

Alsop is furious about his treatment. "Lewisham was a very quick and dirty exercise," he says. "We got paid the paltry sum of £10,000. We were engaged in a visioning exercise, not a detailed analysis, and we did two workshops. They had a mayor with ambitions but then he left and the aspirations went with him. The new councillors haven't done anything. When I talk to people, the biggest problem is their lack of aspiration.

To say it's too aspirational – that's the whole f***ing point!"

Alsop also came in for indirect criticism from Jon Rouse, the former chief executive of CABE, for his use of "big architecture" in masterplanning. Alsop rebuts suggestions that his firm doesn't approach masterplans with enough practical rigour. "We work at values and look at how the plan works in practice," he says, adding that his firm includes specialist planners and even an economist. "I'm not very happy with Jon Rouse – he suggested my vision didn't take these things into account and so didn't work. But where we've worked at Bradford and Barnsley, we've worked on the whole process.

"We've got all sorts of ideas on how to deal with transport and education, how to work with people and how to give them what they want. And what they want is, I can assure you, very much more imaginative than Jon Rouse imagines it might be."

I don't see it as coast-to-coast urbanism
Alsop's idea of a "supercity", a 130-mile long, 20-mile wide strip of the M62 stretching from Liverpool to Hull, has caused a bigger stink than just about anything he's done over the years. And that's saying something.

The idea of a huge metropolis with 15.4 million residents, none of whom would be far from the outskirts of the city or from its central rail line, has turned some stomachs. But Alsop says this is a misrepresentation.

"It's all about giving a sense of identity and putting more settlements in these areas," he says. "I don't see it as coast-to-coast urbanism, but as a series of settlements linked by the M62. My vision for Barnsley is to increase its size and density and establish an identity. Hey presto – people live within a wall that defines the centre."

His vision extends to the motorway itself. "Why shouldn't we rework service stations on the M62?" he asks. "People could drive to these service stations, leave their cars and use buses on the motorway."

Alsop is more sceptical about the recent revival of Manchester. "It's very easy for people in southern England to look at Manchester and say 'It's all happening'. It's not. Even Manchester is one-dimensional. The great key is education, and then keeping the graduates. You need to keep at least 10% of them in Manchester – give them a free office for five years."

Prescott is an extraordinary guy – he can talk the hind leg off a donkey
However, Alsop doesn't have a lot of faith in deputy prime minister John Prescott's much trumpeted Northern Way, a variation on his M62 idea but extended across the whole of northern England. In a recent article, Alsop labelled this "cynical political expediency".

"He's trying to achieve some sort of inclusion for the whole of the north of England. You don't have to do that. Newcastle and Middlesbrough probably have more to do with the economies of Edinburgh and Glasgow than with the M62 area."

Alsop recently shared dinner with other influential architects and Prescott. "He's an extraordinary fellow – he can talk the hind leg off a donkey," he says. "He sat us down and said 'It's your job to give us the wow factor'. I might not call it 'wow', but it's great to have a deputy prime minister who says things like that.

"Contrast that with people like Simon Hughes and Steven Norris, who would take apart the Architecture & Urbanism Unit at the Greater London Authority and farm everything out to separate councils. That's what been happening anyway – that's the problem."

Alsop may not often see eye to eye with authority figures in general, and some London borough councils in particular, but his big vision and energy are a hit with communities, and local people are astute enough see beyond the wackiness of the presentation. When his plans for New Islington in east Manchester were first released, local people weren't put off by the sight of pictures of giant fruit and vegetables sitting among the buildings. "It looks clean and nice," said one resident. And maybe that's all that matters in the end …