When Alan Shearer was first paraded before his adoring Geordie public as a £15m, Premier League winning centre-forward 13 years ago, one of the journalists assembled in the Sir John Hall stand asked, gingerly: "Will the money change you?"

The superstar smiled and without missing a beat said: "No it won't. I'm still a sheet metal worker's son from Newcastle."

That drew a huge, instinctive roar, from the invited suits inside St James' Park, and the thousands thronging outside, in the drizzle, on a working day, embracing Shearer as one of their own.

With Shearer back as the frenetically gum-chewing manager, seeking Premier League survival from four remaining matches beginning tomorrow at Liverpool, it is easy to talk glibly about what Newcastle United means to its supporters and how hideous relegation would be. Fans themselves are weary of the Toon Army tag, Hall's rhetoric about the "Geordie nation" always struck the wrong chord and they deny that their widespread contempt for the club's current owner, Mike Ashley, springs simply from the fact that he and the people he surrounds himself with come from down south.

Yet undeniably a core part of the modern support for the club does spring from the belief that it represents Newcastle itself, the city's history, even its old, lost economy of coal mines and shipyards. All major clubs, of course, embody their fans' sense of local belonging but it is difficult to imagine a new signing at any other club receiving quite such an ecstatic response for mentioning the job his dad did.

"When I was playing for Newcastle United we had good times and there was the same great passion," said Bobby Moncur, captain of the team that won the Fairs Cup, the club's last trophy, 40 years ago this month. "Many more people worked in heavy industry then and the club was woven into that culture; now perhaps, it is something people cling on to."

Moncur has in recent weeks joined the "Al Together Now" rallying calls, emphasising that he believes Newcastle can stay up if they win their two home games, against Middlesbrough and Fulham. The club's managing director, Derek Llambias, says he and Ashley "have a business plan" should the worst happen and Newcastle are relegated from the Premier League, in which they receive around £40m in TV money alone, to the Championship where that figure would drop to £3m. Many believe the players' contracts do not provide for wages to drop on relegation, because Newcastle never contemplated it as a realistic fate; the club would not respond to any questions at all this week.

Michael Owen's contract is up at the end of the season and he would be expected to leave along with Mark Viduka, Alan Smith and a fire sale of others who attract interest. Yet worse even than the financial pain – Ashley would be unlikely to put the club into administration because football contracts would still have to be honoured – is the ignominy of relegation in football terms and for the city's self-esteem.

Of all the Premier League clubs' transformations Newcastle's rebirth, first under Kevin Keegan and arguably continuing, with ups and downs, until the sacking of Sir Bobby Robson in August 2004, most closely reflected Britain's wider economic boom. Hall's repeated cry was that the football club, which he bought for around £3m, would, rebuilt from relegation in 1989 and flush with Premier League cash, be a rallying point for regeneration of the North-East. Battered by the collapse of its industries, Newcastle was looking to a new future spearheaded by Lottery-funded cultural projects, high-tech businesses, tourism and shopping.

"The world will come to Newcastle United," vowed Hall, whose finest career moment was to build a shopping mall, the Metrocentre, on the site of an old ash pit. "The club will be a major industry, marketing the North-East."

Newcastle United's boom had the lot: borrowing, increased ticket prices and mass replica shirt buying which the fans often paid for with credit cards. There was a failure, Robson complained, to invest adequately in long-term infrastructure like the academy and training facilities. Directors' pay ballooned, with thumping annual bonuses for Freddy Shepherd, who became the chairman, and Sir John's son, Douglas, who became a tax exile. In his final year, to June 2007, Douglas was paid £448,654 in salary and a £1.2m pay-off for resigning, all via a Newcastle United company registered in Gibraltar.

The skids the club has hit under a hapless, economising Ashley coincide with recession and Northern Rock remains emblazoned on the players' shirts. Ashley, who made £929m when floating Sports Direct, his business which also flourished in the consumer bubble, never carried out due diligence on Newcastle. Only after he spent £134m buying the club – the Halls reaping £55m, Shepherd £38m, for their shares – did he discover it was steeped in debt. Llambias, former director of a Mayfair casino Ashley frequented, whom Ashley appointed as the man to run the football club, described it in one of his few public statements as "a bucket full of holes".

Ashley was forced to repay £45m immediately and also cleared £18m of loans which bore interest of up to 11.72%. That seemed to soak up much of the cash he might have provided for players, yet Shepherd denies the club was over-borrowed.

"Mike Ashley might say we owed big money but I don't think so," Shepherd says. "Most of it was taken on to build the stadium, and it is a great stadium."

The Halls and Shepherd were shrewd enough to capitalise on the mushrooming of support by expanding St James' Park to 52,000, the third-largest English club stadium after Old Trafford and the Emirates. Even in this dire season, in which Owen has laboured heart-wrenchingly in the incoherent teams managed by Keegan, Joe Kinnear, Chris Hughton as a caretaker and now Shearer, the ground has mostly been stubbornly close to full.

According to Michael Martin, editor of the True Faith fanzine, the modern club still taps into the Geordies' deep seam of belonging, despite the erratic management.

"Newcastle has changed," he reflects. "My uncles worked in the shipyards, my grandfather worked down the pits and as kids we'd go to watch ships being launched at Wallsend. There was romance there, which you don't get now working in call centres. It might sound cheesy, and the rest of the country doesn't get it, but I believe the club filled a vacuum in the identity of Newcastle."

Hall had conjured a vision of the club as a standard bearer for a new Newcastle but a generation of fans like Martin, 45, the sons of sheet-metal workers, shipbuilders and miners, have swarmed to the rebuilt St James' as much for its tradition and links to the past.

The brute truth, anyway, is that marketing, and making a city centre more attractive, can take a city only so far. In July 2006 the Paris-based OECD, a partnership of 30 governments including our own, reviewed Newcastle's efforts to reinvent itself. The report punched hard, finding that, although there were success stories, the North-East economy, employment and incomes lagged behind other regions. The area had the country's worst unemployment among people aged 55-64 – many of them former miners and shipbuilders thrown on the scrap heap while Sir John Hall was building his shopping centre. Too few businesses were starting up compared with elsewhere in the UK. Two companies hailed as beacons were Northern Rock, which afterwards became the landmark first victim of the credit crunch, and Nissan, which in January laid off 1,200 workers.

The council leader, John Shipley, accepted the report as "something of a jolt to the system".

The deputy leader David Faulkner – a season-ticket holder at St James', who believes the fans were "led up the garden path" by the Halls and that Ashley has "misjudged" what was required – says the report showed that economic revival "will take longer and be a harder slog" than previously thought.

Mike Ashley stepped into all this, seeming to gobble up Newcastle United as an impulse buy. He has never explained why: whether he bought the club with a plan to make money out of it or to indulge himself and drink with the masses or both. Either way, for fans who clasp the club as a badge of identity his attitude has been alarmingly superficial. To appoint his friends Llambias and Tony Jimenez, director of a small commercial agency, as "vice-president" for player recruitment – Jimenez is said to have suggested the now departed Dennis Wise as the ideal director of football – as executives for Newcastle United is still discussed with bewilderment ­everywhere outside that circle.

Keegan's return was a populist move which backfired, there were fierce protests at the Hull City match which followed Keegan's departure; Ashley stopped mingling with the fans, made another baffling appointment in Joe Kinnear, announced he would sell the club, returned with Llambias empty-handed from Dubai, then announced he was staying and called for all to pull together. That shaky new tone was then thunderously undermined for fans by the January transfer window, in which Charles N'Zogbia and Shay Given, a club legend, were sold, while Kevin Nolan, Ryan Taylor and Peter Lovenkrands were all he introduced to rouse the soul.

A local consortium is understood to be forming, with Shepherd widely believed to be involved, to buy Ashley out. They are said to have one price if the club survives, a lower one if relegation befalls.

Whatever happens in these final games under Shearer, the last roll of a gambler's dice, Ashley looks likely to face a backlash at the end of the season – not because the fans do not understand that he has put money in, nor that he is from the south, but because at root many feel that the way he has conducted himself has been an insult to Newcastle United and all that the club represents.