Anita Rachman, Jakarta – Former National Mandate Party chairman Soetrisno Bachir has announced his resignation from the party he once led.

Soetrisno served as chairman of the party, known as the PAN, from 2005 until January of this year, before being replaced by Hatta Rajasa, the coordinating minister for the economy and a close ally of President Susilo Bambang Yudhoyono.

Soetrisno had long been at loggerheads with influential party co-founder Amien Rais over the latter's backing of Yudhoyono's re-election bid in 2009, and had preferred supporting rival presidential candidate Prabowo Subianto from the Great Indonesia Movement Party (Gerindra).

Soetrisno did not reply to text messages for comment sent by the Jakarta Globe.

On Monday, Amien played down the significance of Soetrisno's resignation. "If the PAN makes a fuss each time a member leaves, we'll become a small party," he said at an event to mark the anniversary of the party's Aug. 6, 1998 founding.

He added that the Islamic-oriented party would remain committed to upholding the people's interests in economic, environmental, educational and health care matters.

PAN secretary general Taufik Kurniawan confirmed that Soetrisno had resigned, but said he had not yet submitted a formal letter. He also denied that Soetrisno felt marginalized by the current leadership of Hatta and Amien.

"He was a good leader and teacher for five years," Taufik said. "We'll continue to implement his programs."

While Hatta declined to comment, Amien praised Soetrisno's contributions to the party, saying he had been key in steering it to fifth place in the 2009 polls. "If he now opts to join another party, that's his decision and we should respect it," he said.

Meanwhile, party deputy chairman Drajad Wibowo called Soetrisno's departure a loss to the party, adding that he would always remain a good friend.

"I haven't heard from him about what he plans to do next," he said. "I don't know if he'll continue with politics, but lately we felt he was growing more distant from the political stage."

Drajad added he was certain that Soetrisno's resignation would not lead to fragmentation within the party. "We won't have problems in the lower ranks," he said.