Stephen Fitzpatrick, Jakarta – Indonesian leader Susilo Bambang Yudhoyono is expected to start publicly testing the water within days as to who his running mate should be for July presidential polls.

The aim will be to further sow confusion among supporters of the Golkar Party – the vehicle of his current deputy, Jusuf Kalla – as Indonesians go to the ballot boxes for parliamentary elections at the end of next week.

Although Mr Yudhoyono is most likely to still need the support of a fracturing Golkar if his Democratic Party is to form government, he has thus far refrained from engaging in presidential election speculation – other than to make it clear Mr Kalla will not be on his ticket.

Mr Kalla, on the other hand, will almost certainly have to accept the Golkar presidential nomination, in part as payback for an expected poor showing for the party – which dominates the current house – in the parliamentary polls.

There is little expectation, even within his own party, that Mr Kalla could actually win the presidency, with his likely candidacy being seen as a sacrificial act.

According to a source deep within the Yudhoyono team, the most likely partner for Mr Yudhoyono in the July election would be former Golkar chief and one-time parliamentary speaker Akbar Tandjung.

This selection would effectively further split the Golkar vote for the presidential poll. The party, which was the ruling machine of former strongman Suharto, has, besides Mr Kalla, a number of other presidential hopefuls, including media magnate Surya Paloh, Yogyakarta Governor Sri Sultan Hamengkubuwono X and current parliamentary speaker Agung Laksono.

But none of them is an electoral standout and Mr Tandjung is judged by the Yudhoyono team as the one who best performs the contradictory tasks of dividing the Golkar vote – which benefits the Democrats – and yet still bringing the party machine on board for a governing coalition.

"They (Golkar) can't exist without access to key cabinet positions, including the Justice Ministry," the source said. Mr Tandjung would then also replace Mr Kalla as party chairman.

Although the accuracy of opinion polling is questioned, there seems little doubt that Mr Yudhoyono's Democrats will at best attract something under 30 per cent of the national vote next week.

This means that, should he subsequently regain the presidency, he would still be forced into coalition to govern, although with a much stronger hand to play than when he formed his current administration in 2004.

Golkar will most likely hedge its bets by trying to get a candidate in the second spot on all the major presidential tickets, including that of former leader Megawati Sukarnoputri.

Ms Megawati's Indonesian Democratic Party for Struggle (PDI-P) is likely to emerge with a solid bloc in the parliament, but historical animosity makes a PDI-P-Democrats coalition almost impossible.

There is also a distant possibility that, should Golkar collapse completely at the parliamentary polls and the Muslim-orientated Prosperous Justice Party (PKS) pick up part of its vote, Mr Yudhoyono will then stand on a ticket with that party's Hidayat Nur Wahid.

However, the Yudhoyono source also predicted that if the Democrats won outright more than 20 per cent of the national vote – the figure required to field a presidential candidate – he was likely to still do a coalition deal in the house but offer the vice-presidential nomination to his impressive Finance Minister, Sri Mulyani Indrawati.

Although the technocrat Ms Mulyani would bring no party machine to the ticket, she would give a massive boost to Mr Yudhoyono's reform credentials – and if the opposition parties perform poorly, this could be all he needs. But observers have also warned not to place too much stock in current polling figures, saying there could be big surprises after next week.

One, US academic Jeffrey Winters, told a public seminar last week that the biggest problem with Indonesian political polling was that "there is no cross-checking of the results... no one goes back to the villages and actually checks that the people that were supposed to have been questioned were questioned".

One potential dark horse is former Golkar military figure Prabowo Subianto, whose Gerindra party is quickly gathering national momentum. Ironically, the result of a Gerindra success would be a further Golkar downswing since General Prabowo is largely attracting former Golkar supporters.