The European Union wants to offer Serbia a pre-accession pact to trick it into recognising Kosovo, Serbian Prime Minister Vojislav Kostunica said on Monday, warning his pro-EU rivals in government not to sign it.

The fragile coalition of Kostunica's nationalists with the pro-EU Democrats fell in March over whether Serbia should pursue EU membership despite the bloc's support for the secession of Serbia's Kosovo province.

The dilemma is taking centre stage in the May 11 election. Kostunica rejects ties with the EU - such as the Stabilisation and Association Agreement - until it stops backing Kosovo.

"That agreement is obviously in the interests of (EU Enlargement Commissioner) Olli Rehn and (EU foreign policy chief) Javier Solana," Kostunica told state news agency Tanjug.

"It is obviously not in the national interest of Serbia to sign an agreement that would tomorrow be interpreted as Serbia's signing off on an independent Kosovo."

The Democrats, led by Serbian President Boris Tadic, say European Union membership and Kosovo are not related. Their ministers, who had most posts in the outgoing government, say they will sign the SAA in an instant if the EU offers it.

But Kostunica warned that anyone who wants to sign "Solana's pact" can do so only in their own name.

"That signature would bind Serbia to nothing," Kostunica said, adding it would only show that "certain individual parties", not Serbia, had agreed to it.

Brussels has not yet actually offered the SAA, and foreign ministers are due to discuss the issue next week.

Most EU states want to offer Serbia the accord before May 11 to help the Democrats win against the hardline Radicals, support for whom has been fuelled by bitterness at the loss of Kosovo, low wages and stubbornly high unemployment.

The Dutch and Belgians have so far blocked the deal, insisting that Serbia must first deliver war crimes suspects from the Yugoslav wars of the 1990s, such as former Bosnian Serb general Ratko Mladic who is twice indicted for genocide.

EU diplomats say the Dutch might be persuaded to offer the SAA now and have its ratification conditioned on arrests of suspects at a later time.

The condition would mean Brussels could make a goodwill gesture to Serbia's pro-EU camp but without giving up on a long-standing principle, and Serbia would still need to deliver the suspects to have the SAA go into force.

But some analysts in Serbia say the move might backfire with a public fed up with Western conditions and what they see as diplomatic double-talk, and even harm the Democrats.