Former Jakarta governor Basuki Tjahaja Purnama, who was recently released from jail, has joined the political party of President Joko Widodo, just two months before the elections.

Mr Basuki said in Bali on Friday that he has joined the Indonesian Democratic Party of Struggle (PDI-P), the biggest party in Parliament, raising speculation over whether he would be campaigning for Mr Joko, his close ally who is seeking re-election in the April 17 polls.

Active campaigning by Mr Basuki could hamper, not help, the President's campaign. This is because Mr Basuki, a Chinese-Christian politician, is an easy target for Islamic conservatives and hardliners, a group largely seen as being against the re-election of Mr Joko.

Mr Basuki lost in the 2017 gubernatorial election after his opponent played the religion card, triggering massive street rallies involving tens of thousands of Muslims protesting against him. Mr Basuki was later convicted of blasphemy against Islam. He was sentenced to a two-year jail term and released on Jan 24 after getting remission.

A senior PDI-P official said yesterday that Mr Basuki, widely known by his Chinese nickname Ahok, will not be involved in the ongoing presidential campaign because of personal matters. PDI-P secretary-general Hasto Kristiyanto told The Sunday Times: "He will not take part in the campaign as he has his own agenda abroad for 21/2 months."

Mr Basuki, 52, had indicated that he would soon marry his girlfriend Puput Nastiti Devi, 21.

Mr Hasto said that as an ordinary party member, Mr Basuki will be given assignments and undergo processes such as political training.

Mr Basuki's political career is closely watched because of his meteoric rise before his downfall.

He began his political career by becoming a member of the regional legislative council in his native East Belitung regency in Bangka Belitung Islands province in 2004, through the New Indonesia Alliance Party. He was also a member of Indonesia's major parties Golkar and Gerindra. The latter's leader Prabowo Subianto is challenging Mr Joko in the presidential polls.

In the run-up to the 2017 gubernatorial election, Mr Basuki was poised to make history as the first elected governor of Jakarta who was not only Chinese but also Christian. But his straight-talking manner and championing of pluralism, which endeared him to many, also saw his opponents turning that against him.

Experts have pointed out that since his release from prison, Mr Basuki has refrained from speaking about politics so as not to jeopardise the re-election bid of Mr Joko.

The incumbent is leading in the presidential campaign against Mr Prabowo, but with three more televised debates in the next few weeks, the campaign dynamics could change quickly over the next two months. The debates feature both the presidential candidates and their respective running mates, senior cleric Ma'ruf Amin and former businessman Sandiaga Uno.

Mr Arya Fernandes, a political expert from the Centre for Strategic and International Studies, said that Mr Basuki's role in PDI-P and in politics will not materialise soon.

The party has to assess what will be an appropriate position for Mr Basuki and the impact he will bring to the party. He also needs to adapt to its political culture, which is different from that of his previous parties.

"The internal political patronage in PDI-P is very strong, while Ahok is typically a free and open person. So political adaptation remains his challenge," Mr Arya said.