Man with a plan: Berlusconi believes he has solved problem

Spain and Poland are refusing to give up a generous package of EU voting rights which they won three years ago.

Mr Berlusconi announced on Wednesday he believed he had a solution.

The issue - together with a separate defence row - is threatening to bring down the entire constitution at this weekend's summit in Brussels.

I will pull the formula out at the last minute and we will see if it will be accepted by these two countries Silvio Berlusconi

"I have in my pocket a formula which I believe gives Poland and Spain recognition as big countries," said Mr Berlusconi, who has the task of solving the crisis because Italy holds the EU's revolving presidency.

"I will pull it out at the last minute and we will see if it will be accepted by these two countries."

The row centres on a promise won by Poland and Spain at the Nice summit in 2000, giving them 27 votes each on Europe's powerful Council of Ministers.

That compares to 29 for the much-larger Germany.

Deadlock

The draft constitution tries to redress the balance, but Spain and Poland have refused to back down.

France and Germany on the other side of the argument have also dug their heels in.

Mr Berlusconi, refusing to give any hint of his solution, also rejected the idea of a two-tiered Europe if the summit failed.

Italy has said it would prefer no deal at all to a bad deal.

'Marathon'

"I am very hopeful about the outcome of this marathon effort, but I am also conscious of the difficulties that lie ahead," Mr Berlusconi said on Wednesday.

Other countries have also warned that failure to reach agreement is a possibility.

The separate issue over mutual defence has concerned neutral EU states Austria, Finland, Ireland and Sweden.

The clause says that if any member is "the victim of armed aggression on its territory, the other member states shall have towards it an obligation of aid and assistance", but the four say their neutral status could be threatened.