Britons believe UK entry to the euro to be less likely, finds official EU research.

Brussels' spring "Eurobarometer" survey has charted a seven per cent drop in those believing the UK will join the single currency.

The number thinking that Britain will stay outside the eurozone has risen to 28 per cent.

Results indicate that continuing government delay on a date for a referendum on entry to the single currency may be damaging the pro-euro cause.

And ministers will be dismayed to find that despite introduction of the euro on European mainland UK unhappiness with the single currency continues to top the charts.

British "unhappiness" with the prospect of joining the single currency has risen one point to 55 per cent.

But figures have not yet been compiled for the summer period - when millions of UK tourists sampled the euro at first hand.

Fifty nine per cent of Britons continue to be worried over the prospect of difficulties created by the introduction of the new currency - but the figure has dropped five points since euro notes and coins went into circulation.

The UK has maintained its level of concern that prices will rise with the new currency - 49 per cent.

A view that is becoming generally accepted across the eurozone.

Four fifths of Europe's citizens - 83 per cent - now believe that the single currency was introduced to their disadvantage.

Numbers of euro-citizens feeling short-changed have increased by 16 per cent - with larger swings registered in Austria and Italy.

Overall Europe is increasingly unhappy with their new currency.

The happiness indicator has dropped three per cent.

But the satisfaction index - 62 per cent - is still greater than the 43 per cent concerned before the euro was introduced.

Germany is increasingly unhappy - with the number of discontented rising 10 per cent in March and five per in May - over half the population is now unhappy with the demise of the Deutschmark.