Jakarta Governor Basuki "Ahok" Tjahaja Purnama has challenged possible rivals in next year's Jakarta gubernatorial election to focus on improving the capital rather than on undermining him.

Candidate hopefuls should reveal their programs so that Jakartans have clear information on programs that would best suit them, Ahok said on Tuesday.

"So it would not only be to band together to beat Ahok. I feel sorry for Jakartans if that's what you aim to do. If you want to beat Ahok and succeed, what then? You need to have clear programs," he told journalists at City Hall.

Ahok said he welcomed the competition with other regional leaders in the election, saying that the experience of a regional leader was a strong point for someone to lead the capital.

"If you have been a regional leader and held power, your character will be revealed. For example, whether you dare face the City Council, have a transparent budget and whether the public is satisfied with your work. That's the key," Ahok said.

Surabaya Mayor Tri Rismaharini and Bandung Mayor Ridwan Kamil have been encouraged to vie for the capital's top post, but both have declared that they will not contest the election.

Ahok has declared that he will run in next year's election with running mate Heru Budi Hartono, currently the head of the Jakarta Financial and Asset Management Board (BPKAD).

Two political parties, NasDem and Hanura, previously declared support for the incumbent governor, who has decided to run as an independent.

The Golkar Party, the Indonesian Democratic Party of Struggle (PDI-P), the Gerindra Party, the Prosperous Justice Party (PKS) and the United Development Party (PPP) have declared that they will set up a coalition to nominate a gubernatorial candidate to challenge Ahok.

The five political parties control 70 of the 106 seats in the Jakarta City Council. With 25 seats, the PDI-P is the largest political party in the city, followed by Gerindra with 15 seats, the PKS with 11 seats, the PPP with 10 seats and Golkar with nine.

The coalition believes it can increase the electability of a candidate of its choice, Golkar's Jakarta branch secretary Zaiuddin said in Jakarta on Thursday. (rin)