As 12 European states prepare to adopt euro notes and coins, some of their neighbours in central and eastern Europe are wishing that they too could be part of the action.

Estonia signalled three years ago that it wanted to adopt the euro as soon as the notes and coins were introduced.

Meanwhile, the governor of Poland's central bank is also yearning to abandon the zloty in favour of the new currency.

For many of the 12 candidate countries, adopting the euro before they join the European Union represents a chance to impose fiscal discipline and bring inflation down to western European levels.

Pushing through economic reforms has proved perilous for many governments in the candidate states and some believe that impending euro entry would spur citizens to accept bitter medicine.

Other central and eastern European governments see lower euro-zone interest rates as a chance to cut the size of their national debt.

Few eastern Europeans are sentimentally attached to their national currencies and many have savings in deutschmarks that would be automatically converted into euros.

Besides, a number of the candidate countries have already pegged their currencies to the euro or seek to shadow the single currency in their exchange rate policy.

The European Central Bank (ECB) and the European Commission are usually keen to trumpet the virtues of the euro and to encourage the laggardly British, Swedes and Danes to adopt it. But they have given a distinctly frosty response to the candidate countries' overtures.

The ECB vice-president, Mr Christian Noyer, said recently that it would be a mistake for candidate countries to adopt the euro unilaterally, not least because it would impose tough anti-inflationary policies that could prevent incomes from rising rapidly.

Incomes in most candidate countries are at present between one-third and one-half of the EU average and the strong economic growth needed to boost them is likely to create inflationary pressures.

Mr Noyer suggested that a few years of inflationary growth would not do the candidates any harm and that introducing up to 10 poor, new members into the euro zone could create problems for everyone.

Under European Union rules, candidate countries must spend two years in the Exchange Rate Mechanism before joining the euro and must fulfil all the regulations on inflation, budget deficits and public debt.

If, as EU leaders announced at the Laeken summit, 10 countries are ready to join the EU in 2004, they could not expect to join the euro zone until 2006.

Many economists, including those attached to Germany's Bundesbank, believe that 2008 is the earliest date at which the first candidate country would be ready to adopt the euro. The prospect of enlarging the euro zone provides another headache for the ECB in the shape of a bloated Governing Council.

At present, each euro-zone member-state has a seat on the Council, along with six executives based in Frankfurt, making a total of 18.

Many observers believe that number is already too great and they fear that a Governing Council of 28 or 30 would be unable to make decisions effectively.

Besides, many of the candidate countries are likely to experience high economic growth and strong inflationary pressures for many years to come, putting them in a position more similar to the Republic than, for example, Germany.

The ECB's nightmare is that a majority of euro-zone member-states could demand a monetary policy more suitable to the Republic than to Germany, even though they would only account for about 20 per cent of total euro-zone gross domestic product (GDP).

A change in the ECB treaty requires the approval of all EU member-states and the row at Nice over reducing the size of the Commission indicates that unanimous approval for reform of the Governing Council would be difficult to secure.

If the European Union does not act quickly to reduce the Council's size, it could face more difficult horse-trading after the first new member-states join.

In the meantime, the message from Brussels and Frankfurt to the candidate countries is "be patient and your time will come to join the euro".

But nobody is predicting just when that time will come.