Even on a grimly wet Tuesday afternoon in November, southern drivers are competing for the few remaining spaces in front of Sainsbury's supermarket in the Quays Shopping Centre in Newry.

On this weekday, local shoppers from the Co Down and Armagh hinterland are more in evidence – but on weekends, the southerners get a free run to exercise their purchasing power with the mighty euro. The so-called Northern shopping phenomenon became firmly established ever since the currency started on its huge climb against battered sterling. But that was 30 months ago, and since there has been little sign of southern stores passing on the full purchasing clout they enjoy sourcing goods on world markets, shoppers from the Republic continue to trek up and across and down to centres like Newry.

It makes it all the more remarkable that the thousands of shoppers who weekly fill the 1,200 car-parking spaces in front of one small supermarket in a modestly sized shopping centre an hour's drive from north Dublin should attract a barrage criticism from a Tánaiste, a finance minister, a former Dublin mayor, and assorted vested interests, including employers group Ibec.

No surprise then that the flak lobbed in the direction of Newry is again increasing in the run-up to the Christmas.

The owner of the Quays, property developer Gerard O'Hare, known as Mr Newry for his part in fashioning the Co Down town shopping malls, has been accused of nothing less than promoting national bankruptcy – helping to rob the diminished Dublin exchequer's coffers of €430m in Vat and excise revenues.

From his office in a refurbished stone-clad old mill building that bookends the Sainsbury car park, O'Hare (51) does not appear to be the type to be plotting the ruination of the Irish nation, north and south. His immediate family was a leading contractor, O'Hare McGovern, which still builds Boots, McDonald's and Eason shop fronts and schools across Ireland.

As a young quantity surveyor trainee, O'Hare learned about shopping centres, cycling around Dundalk, working for the late Phil Monahan's Monarch Properties, the developer of Dundalk, Tallaght, and Navan shopping centres.

O'Hare hit the jackpot with a site in his home town because the euro moved spectacularly in the right direction. He bet on the Quays, which he bought 10 years ago on the site that older drivers on the former Dublin-Belfast highway will recall as one of the two coal yards that sat at the town end of Newry's shipping canal.

After selling his stake in the nearby Buttercrane centre to John McGuckian, his successful development of the Quays led to purchases of the Fair Green shopping centre in Carlow, buying a 21.5 acre site in Waterford adjacent to the crystal factory, and, more recently, the purchase of half a dozen projects in cities in central Europe and a $100m acquisition of a shopping centre in Connecticut.

He also has smaller developments in Belfast and Dublin, including office and retail space diagonally across the street from the Department of Finance.

Funding most of the small empire is approximately €200m in borrowings from Anglo Irish. The success of the Quays makes his company among only a handful of Anglo property developers who meet their monthly interest payments in full to the bank.

Ironically, the rent roll spinning off Newry's Quays, criticised by Dublin government politicians and retail vested interests in the south, is evidently helping O'Hare pay his interests payments to Anglo, a bank owned by the southern taxpayer-shoppers spending their euro in Newry.

"We would not be one of Anglo's biggest. But we would not be one of the distressed ones. We are still very solid. We are collecting our rents and we able to pay our debts. We are one of the few in Anglo who are good, who have survived and who are solvent," O'Hare says.

But even Ireland's most solvent developer is not without his worries. He relates that just over a year ago, in the first week of September, a number of unnamed banks, including presumably Anglo, had committed €440m of the €770m he estimated he needed to fund developments in Waterford, Carlow and Slovakia, and to double the space in Newry. By Christmas, the banks had withdrawn their €440m.

Anglo in the future will be unable to fund him but, says O'Hare, other Dublin banks, and Austrian and German lenders, will provide the finance.

He insists that the battered Waterford and Carlow city economies will provide enough demand to fill his shopping centres there. "Newry is bucking the trend. We are up 25% to 30% year on year. The rest of the world is down 5% to 15%. People still want to be in. In Carlow, I have my directors meeting in London today with two major, major retailers for our next phase in Carlow."

He says French telephone sales company Teleperformance, which already provides 1,000 jobs in Newry, will rent space from him to create up to 500 IDA grant-assisted jobs in the 21.5 acre Waterford site, where he plans to start development in the next few months.

And despite the slump in Irish retail spending, he insists that international retailers are looking four to five years ahead to rent shops here.

But it still all comes back to Newry. Registration documents of his Parker Green companies registered in Dublin and Belfast show that Anglo, in return for funding in Waterford, has charges over the Newry Quays, a petrol station, a tyre depot, other office space in Newry and a personal guarantee. O'Hare plans to start development on the Quays with an adjacent site, doubling the car spaces and Sainsbury's retail space.

In short, it is a bet that the euro will not slide back any time soon against sterling. It is also probably a safe bet that southern shoppers will continue to roll up in Newry, as their local stores fail to pass on the benefits of the strong euro.

'I was never invited to join the golden circle'

O'Hare says that he was never one of the "golden children" of Anglo and was therefore not invited last year to make up the numbers of the so-called 'Golden Circle' of businessmen whom Anglo funded to buy its own shares, which mopped up some of the stake created by Sean Quinn's stock market dealings.

"I was never invited to join the Golden Circle. In fact, I only met Seán [FitzPatrick] once, for two minutes, at an Anglo luncheon before a rugby match," he says. "I was not a big customer in those guys' eyes. I was too conservative, too reluctant to play the big game. I was a good stable customer. That is why I am still here today and they are not distressed about me."

His Parker Green International company, whose advisory board includes Bertie Ahern and the former unionist politician Lord Dennis Rogan, was pipped by just €10m for the Swords Pavilion shopping centre by developer Joe O'Reilly. "We bid €575m and Joe bid €585m plus 9% stamp duty and that was in 2007. We got a bit carried away because we were approached by AIB's Investment arm – Goodbodys – to be their partner. And that gives you a bit of an ego run if a bank comes and offers to stand with you on €1bn deal, as it was then."