Lindsay Murdoch, Jakarta – President B.J. Habibie's campaign to be elected at June polls suffered a serious blow yesterday when three main Indonesian opposition parties formed a united front against him.

Opposition leaders agreed to put aside key policy differences, including on East Timor, to form a bloc for the country's first free elections in 44 years.

Diplomats and observers say that Dr Habibie, already under attack for his administration's links to the discredited former president Soeharto, will struggle to win enough votes to to stay in power after the June 7 poll.

They said Dr Habibie's only hope was to spend millions of dollars buying votes and the support of smaller parties.

A deal uniting the three parties was sealed early yesterday morning despite the initial reluctance of Ms Megawati Sukarnoputri, the leader of the Indonesian Democratic-Struggle party.

Under the deal, the opposition party that wins the most votes at the elections will get the backing of the other two parties to nominate the next president when the parliament meets in November.

But the deal falls short of forming a coalition as each will field its own candidates and campaign on separate policies.

Party sources said Ms Megawati was particularly concerned about joining forces with the reformist National Mandate party of the Muslim leader, Dr Amien Rais, whose policies include giving wide autonomy to Indonesia's far flung provinces through a federation-type system.

But Ms Megawati was convinced by another Muslim leader, Mr Abdurrahman Wahid, also known as Gus Dur, in a late-night meeting that she should put aside policy differences to form a block to sabotage Dr Habibie's Golkar party.

Mr Wahid chairs the country's largest Muslim group, Nahdlatul Ulama, and leads the National Awakening Party, the third force in the united front.

Under Mr Soeharto's military-backed rule the Golkar party, which is now deeply divided, crushed rival politicians to rig six elections over 32 years.

A recent poll in the respected Kompas newspaper showed the three parties in the new alliance having 41.5 per cent of voter support while Golkar's support was only 14.3 per cent.