Woe betide Dutch retailers that use the impending switch to euro notes and coins as a cover for putting up prices. They face a public pillorying on the website of the Consumentenbond, Europe's largest national consumer association.

The Dutch language site (www.consumentenbond.nl) lists what it calls EuroMissers - organisations reported by its 640,000 members for a variety of faults, such as providing inadequate information to consumers, or rounding up prices.

Nicole Fontaine, president of the European Parliament, called late last month on other countries to set up similar initiatives. She was awarding - to a local insurer that had rounded down all its premiums - the Consumentenbond's first monthly "euro plume" for a business carrying out the change to the benefit of customers.

In the doghouse are groups such as Golden Tulip, the biggest Dutch hotel chain, which is owned by Spain's NH Hoteles. It is accused of charging unpayable guilder prices for drinks: a beer listed on its menus at E1.85 works out at Fl 4.08, whereas the absence of guilder cent coins means that a drinker actually pays Fl 4.10.

Golden Tulip is merely adopting what has long been standard practice at Dutch supermarkets. They price items at psychologically attractive amounts ending in 99 cents, knowing that this has to be rounded up.

But because the retail sector in the Netherlands is coming under intense scrutiny, a public that is both price-conscious and knowledgeable - nearly two-thirds feel "very well" informed about the euro - will not meekly allow the switch to happen to its detriment.

Half the population suspects that prices will be sneaked up, opinion polls show. The Dutch central bank, in common with the European Central Bank, says it is aware of the inflationary risk and will be monitoring retail pricing, but has few fears.

Nout Wellink, bank governor, says it "is a good thing that the public is distrustful", because it makes people alert. "This will put a brake on possible abuse."

The Dutch national forum for the introduction of the euro - grouping government, employers and unions - has called on each organisation to ensure that the total effect of its pricing policy is neutral. That forced the Justice Ministry to retreat from a planned rounding up of court and police fines by up to 10 per cent.

"Fears of price rises with the introduction of the euro are increasingly undermining the trust of the consumer.

"This distrust appears, however, misplaced," the forum has said.

Half of all Dutch retailers already display prices in both currencies. From next month dual pricing is required under a pact between the Consumentenbond and HBD, the industry association. HBD is calling on members to "make sure in the transition period that price changes have a clear cause".

Movements in costs such as energy can still be passed on, leaving shops a fair amount of freedom to determine how individual articles should be priced. But retail strategists say those who handle the change in a less than customer friendly way risk long-term damage to their public image.

The decision is trickiest for supermarkets, where margins are thin and psychological pricing is regarded as most important.

An item currently selling at Fl 9.99 is strictly worth E4.53326. In the necessary rounding down to the nearest euro cent, the store already takes a small hit. An additional cut to a more attractive E4.49 would, for something leaving the shelves at the rate of 100m units a year, lose the retailer E4.3m.

As in all euro-zone countries except Ireland, the larger euro unit will also change perceptions. As a result, a store's own-label item that previously sold for a guilder less than the branded equivalent will soon be only E0.45 cheaper, removing some of the appearance of price advantage.

To counter this, retailers can round down aggressively and hope to offset that by a boost in market share. They can attempt to shift the cost burden to suppliers. They can vary the content of at least their private-label lines to produce a more eye-catching euro price without losing profit.

Store groups point out that they are used to handling the temporary loss of psychological pricing when a national value-added tax rate is altered. But this time shoppers are expected to be more vigilant about goods that go up if the nearest "price point" is in that direction.