The BBC's William Horsley: Romano Prodi has shocked some EU members with his ideas

European Commission President Romano Prodi has ordered three of his most senior advisers - the so-called panel of wise men - to report on options for radical reforms to the EU's institutions as it prepares to almost double in size over the next decade.

Correspondents say the potential admission of up to a dozen mainly east European countries makes a pressing case for a review of how the EU functions.

The BBC's European Affairs Correspondent William Horsley says that, in broad terms, the report will suggest ways of letting the European Union function more like a sovereign government.

In their report, the group of wise men - former Belgian prime minister Jean-Luc Dehaene, former BP chairman and British Labour peer Lord David Simon and former German president Richard von Weizsacker - are expected to recommend limiting member states' powers to use national vetoes.

Romano Prodi: Plans for "European" government

This would take away some of the rights of national governments to stand in the way of new laws and policies which they oppose, and give increased powers to Commission officials and the European Parliament, our correspondent says.

The size of the Commission could also be tackled with the abolition of the right of the bigger nations, including the UK, to send two commissioners to Brussels.

These proposals will be discussed at an Inter-Governmental Conference on the future of the union next year.

Opposition expected

The European Union is already committed to streamlining its decision-making before the first new members join, in a few years' time.

But such radical proposals are likely to encounter strong opposition from some member states.

The UK Government is one of several which oppose new powers for the Commission and the European Parliament.

UK opposition leader William Hague recently declared a new "battle of ideas" against a European super-state, while Prime Minister Tony Blair says a closer partnership with the EU is good for Britain.

The UK Government has made it clear that the involvement of Lord Simon does not imply any official support for the report's conclusions.