Armando Siahaan – Sri Mulyani Indrawati left Indonesia to take up her new post at the World Bank on Wednesday leaving behind words of caution for the country's ability to continue financial reforms in the face of entrenched political opposition.

In her strongest comment on her departure yet, the former finance minister told Britain's Financial Times newspaper that her efforts to reform the country's economic system had been hijacked by a group of business and political interests that left her no choice but to accept the bank's offer to become a managing director. She begins her new job in Washington, DC, on Tuesday.

Meanwhile, her public crusade against tax evaders, especially those linked to Golkar chairman Aburizal Bakrie, received a blow after the Supreme Court ruled in favor of mining company PT Kaltim Prima Coal, part of the Bakrie Group interests, in a Rp 1.5 trillion ($160.5 million) tax-evasion case.

In March, the Directorate General of Taxation filed a case review to the Supreme Court three months after the Tax Tribunal ruled that the taxation office had not obtained sufficient grounds to investigate the company, which is the coal-producing unit of PT Bumi Resources.

The Supreme Court Web site said a three-member panel of judges on Monday rejected the case review, supporting the lower court decision. Court spokesman Andri Sutrisna confirmed that it had ruled in favor of Kaltim Prima.

In the FT interview published on Wednesday, Sri Mulyani warned: "The business community is not supportive of having the system co-opted for very personal, narrow interests. If they start to allow one party to hijack it, it is at the cost of everyone else... It is really a concern. It is a battle for Indonesia now."

Sri Mulyani has openly admitted that her decision to leave this month was greatly affected by concerted political attacks during her time as finance minister.

It has been no secret that Sri Mulyani has been involved in a feud with businessman-cum-politician Bakrie, as she has pressed tax-evasion cases against several companies connected to his massive conglomerate.

Conversely, Golkar Party lawmakers in the House of Representatives have been aggressive in trying to oust Sri Mulyani through the use of a special investigation into alleged wrongdoing connected to the 2008 bailout of Bank Century during the height of the global financial crisis.

Last week, in remarks widely seen as a swipe at the alliance between Golkar and the ruling Democratic Party, she said she could not have a role in a political union that was bad for the country. Two days after her resignation, a new coalition joint secretariat was announced, with Bakrie as its managing chairman, leading to suspicion that she was pushed out of office.

The newspaper said she singled out Bakrie as the main force behind the opposition to her reforms. "It's [Bakrie]... but I'm not denying that there aren't others," it quoted her saying.

She has also said that while she was not forced out, the president did not prevent her from leaving, either.

A spokesman for the Bakrie family told the Financial Times that her departure was not due to strained relations with Bakrie.