The fallout from the conviction of a junior tax official, Gayus Tambunan, on corruption charges has revealed deep rifts in the coalition government led by the president, Susilo Bambang Yudhoyono. In January Mr Tambunan was sentenced to seven years in prison after a trial that uncovered deep and ingrained graft in the Directorate-general of Taxes (DJP). Following the sentencing of Mr Tambunan, the president ordered the investigation of companies that had allegedly conspired with Mr Tambunan to avoid their tax obligations. Among the firms from which Mr Tambunan claimed to have received bribes in exchange for favourable tax treatment are three mining firms, Bumi Resources, Kaltim Prima Coal and Arutmin, that are owned by the family of Aburizal Bakrie, the chairman of Golkar (one of the parties making up ruling coalition).

To counter this threat to his business empire, Mr Bakrie appears to have used his influence in the House of People's Representatives (DPR, the legislature) to launch a proposal for a formal enquiry into tax corruption, with the Prosperous Justice Party (PKS) joining Golkar in backing the plan. Although Golkar and the PKS are the second- and third-largest parties respectively in Mr Yudhoyono's coalition, their narrow interests frequently cast them in opposition to the president. On this occasion Mr Bakrie may have hoped that a full-scale parliamentary probe would discourage the government from pursuing investigations into his companies with due vigour and cause it to turn its attention elsewhere. An enquiry of this nature would have put severe pressure on Mr Yudhoyono's administration, drawing government ministers and senior officials into months of questioning. It would potential also mean that the president might ultimately be held accountable for his failure to deal with tax graft. A similar parliamentary enquiry into the bailout of a medium-sized lender, Bank Century, in late 2008 was used to harass the government and led to the resignation of a reformist finance minister, Sri Mulyani Indrawati.

Mr Yudhoyono's Democrat Party (PD) was opposed to the setting up of a special enquiry, and instead argued that oversight of ongoing tax-corruption cases should remain with a lower house committee, House Commission III for legal affairs. The PD's argument prevailed, and the proposal to establish a special enquiry was voted down narrowly in late February. Senior PD figures have now indicated that they will conduct an evaluation of the composition of the coalition, with Golkar and the PKS being subject to particularly close scrutiny. Mr Yudhoyono's consensual approach to politics, as well as the arithmetic of parliament, means that a major shake-up is unlikely. But the divisions between the coalition parties are now clearer than ever, with Mr Bakrie acting as a brake on reform, Golkar and the PKS functioning as a self-serving virtual opposition within the government, and Mr Yudhoyono being drawn closer to allies in the National Mandate Party and the People's Awakening Party, on which he depends (along with Golkar and the PKS) for a majority in the legislature. Furthermore, the divisions and the influence of vested interests over policymaking means that it is unlikely that any further substantial reform will emerge from Mr Yudhoyono's second-term administration.