Salim Osman, Nusa Dua (Bali) – Vice-president Jusuf Kalla, 62, was a picture of confidence when he walked up the stage at the Westin Convention hall here on Sunday to deliver his victory speech.

Fresh from being elected chairman of Indonesia's largest political party Golkar, Mr Jusuf outlined his vision for the party, insisting that it will keep a distance from the government to retain its credibility as a party that provides the checks and balances in the system. "If the government is wrong, it is important for the party to criticise," he said.

It was quite a statement from the businessman-turned-politician who had surprised everyone by seizing control of the country's major political party.

In one fell swoop, he had turned the party's position around from being the main opposition force against the Yudhoyono-Jusuf administration, to lining it up as a main political backer for the new government.

And in one bold stroke, the diminutive Mr Jusuf has bolstered his own hand within the government, adding to the already significant influence he wields in the administration of President Susilo Bambang Yudhoyono.

In one sense, his victory will be a relief to Dr Yudhoyono and his team, who faced a hostile Parliament dominated by Golkar and its allies in the Nationhood Coalition. Golkar parliamentarians had seized the top parliamentary posts and even blocked the Indonesian leader over who should be named the new military chief.

"Mr Jusuf's chairmanship will indeed bring respite to Dr Yudhoyono in dealing with a fractured Parliament," said Mr Arbi Sanit, an analyst from University of Indonesia.

The new chairman is expected to bring the party in line with the government, paving the way for the President to push through much-needed policies to fulfil his election pledges.

Mr Bomer Pasaribu, head of the Golkar convention and an ally of ousted chairman Akbar Tandjung, acknowledged that Mr Jusuf's win would alter Golkar's focus. "There will be shifts in Golkar and the Parliament after this. But I think we have to maintain the position as a partner that will remain critical of the government," he said.

The Nationhood Coalition which Golkar leads in partnership with the Indonesian Democratic Party – Struggle of former president Megawati Sukarnoputri is likely to break up before long, as it hinges on Mr Akbar. It was formed just days before the September presidential election to prop up support for Ms Megawati in her failed bid at re-election.

But there are concerns among analysts that Golkar might return to its old position of being a rubber stamp for the President and his deputy. "Golkar has again become the ruling party and the Nationhood Coalition has collapsed," Soegeng Sarjadi Syndicated director Sukardi Rinakit was quoted as saying by the Antara news agency. "The House may again become a rubber stamp, as it was during the New Order era, as Golkar may completely support the government."

Parties now aligned to Dr Yudhoyono's Democrat Party in the people's coalition might also break away to form the opposition. Already, faction leaders from the Indonesian Mandate Party and the Muslim-based United Development Party have threatened to cross over.

If that happens, Dr Yudhoyono may have to contend with this group of minor parties in the House. But a bigger worry for the President might well be whether he is able to control his ever-more powerful deputy. "We will have two presidents leading Indonesia. One a de jure president in the form of Dr Yudhoyono. The other a de facto president – Mr Jusuf," Mr Arbi told The Straits Times.

Previous vice-presidents played largely ceremonial roles. But Mr Jusuf is the leader of the largest political party, with 23 per cent of the seats in Parliament. On the other hand, Dr Yudhoyono is the leader of a tiny party which controls just 10 per cent of the House.

Mr Jusuf already wields considerable power within the administration, having had a hand in the appointments of several Cabinet ministers, including Chief Economic Minister Aburizal Bakrie and Justice Minister Hamid Awaluddin. He has also called for a more aggressive fiscal policy at a time when Indonesia is under pressure to rein in its budget deficit.

Analyst Indria Samego is among those who see signs of trouble ahead. "We can't rule out the possibility of a rivalry in the palace between the two leaders," he told The Straits Times.

Respected Golkar elder Suhardiman is even more blunt. "Mr Jusuf will be the enemy within for SBY," he said, referring to the President by his initials.

Mr Mohammad Qodari of the Indonesia Survey Institute shares this view, telling Reuters news agency: "Right now, we have two suns in the country. If they work together, shining on Indonesia, it will be good for the people... But if they don't, they will burn the people."