JAKARTA, May 1 (Xinhua) -- Indonesia's five big parties declared a big coalition for parliamentarian level on Friday to challenge the President Susilo Bambang Yudhoyono's Democratic Party, the private television station MetroTV reported here.

    The parties involved in the coalition were the Indonesia Democracy Party of Struggle (PDIP), the Golkar Party, the Great Indonesia Movement (Gerindra) Party, the People Conscience (Hanura) Party and the Unity and Development Party (PPP). Six other smaller parties were also involved in the coalition.

    Yudi Latif, a political observer, said that the coalition would be the Democratic Party's strong rival in parliament.

    "If they are solid, they would be a tough contender for Democratic Party because they would control more than half in parliament," he said.

    Manual tabulation by the General Election Commission (KPU) showed that as of Thursday, PDIP led the election tally (19 percent), followed by President Yudhoyono's party (17 percent) and the Golkar Party (14 percent).