It was a highly anticipated switch of alliance in Indonesia that would significantly shift the balance of power in South-east Asia's largest nation.

Yet, the opposition Golkar party's much-touted move to back the Joko Widodo government - thereby boosting the President's reform agenda - almost did not materialise.

This even though it was widely expected that Golkar chairman Aburizal Bakrie would make the announcement at the close of the party's three-day leaders' conference which started on Saturday.

The businessman and tycoon, who goes by the moniker Ical, left it till late on Monday night. In fact, it was so late that what was the biggest news in local politics since the start of this year did not even make the press the next morning.

Yesterday's edition of The Jakarta Post, the country's main English broadsheet newspaper, reported that Mr Bakrie was delaying the move until Golkar's national congress, which party cadres have yet to decide when to hold.

"We declared that we would oppose the government at the last national congress (in December 2014), so it takes another national congress to change," Mr Bakrie had said.

Between the time he said that and the newspaper's press time, however, the deal was done.

The party's declaration to support the government was signed, sealed and delivered to Mr Luhut Pandjaitan, who is Coordinating Minister for Political, Legal and Security Affairs and one of the government's representatives, at the end of the meeting.

As the first Indonesian president to have established a minority government, Mr Joko often had to deal with an incendiary opposition in Parliament (DPR).

This alliance will give his administration an arithmetic edge, raising the odds for the President to push through much-needed reforms and policies, including government projects that will help generate jobs and turn the country's faltering economy around.

Speculation over the switch had been circulating for months, but it came to a head two weeks ago when Mr Bakrie pledged Golkar's support after meeting Mr Joko on Jan 11.

"We want the government to be able to realise its vision and mission and carry out steps to develop the nation to help our people," he had said then.

Golkar is part of the opposition Koalisi Merah Putih (KMP), or Red White Coalition, but it is also the second-largest party in the House, having won 91 seats in Parliament at the 2014 legislative polls.

That is just behind the 109 won by Mr Joko's Indonesian Democratic Party-Struggle (PDI-P).

The ruling coalition controls 256 of the 560 seats in Parliament but this could rise to 347, or 62 per cent of the House, with Golkar's support.

Add the backing of other KMP defectors such as the National Mandate and United Development parties, which had previously supported Gerindra politician Prabowo Subianto's presidential bid, and Mr Joko will have friends in almost three-quarters of the House.

Political observers, however, say that the promise of quick reforms, which used to be held back by the majority KMP opposition, will come at a price - specifically what motivated Golkar to switch sides, and what the President had to trade for its support.

Associate Professor Leonard Sebastian, of the S. Rajaratnam School of International Studies, believes Mr Bakrie is positioning Golkar to take advantage of a possible Cabinet reshuffle, which has been on the cards for months.

"The rumours are that there could be a reshuffle at the end of the month and Ical is aware that Jokowi needs Golkar support to push through his policy agenda and balance against the PDI-P in the DPR," he said. "If bringing Golkar into Jokowi's coalition results in gains for the party in terms of Cabinet positions or other material benefits, then Ical can further consolidate his position in Golkar."

Economist Wellian Wiranto, from OCBC Bank, says that the support from Golkar will free Mr Joko from relying on the PDI-P when pursuing his agenda.

Prof Sebastian agrees, saying that having failed to secure unconditional support from the PDI-P for his policy objectives, Mr Joko has now opted to put aside his pledge to build a government on a slim coalition or Koalisi Ramping, and instead has turned to the power-sharing model, which has been a mainstay of modern Indonesian politics since 1999.

"Political conditions have given him little choice but to return to a tried-and-trusted model to consolidate his rule," said Prof Sebastian.

Many will hope that the alliance will translate to a more effective Parliament. It passed only three Bills last year, the lowest in the past five years.

Still most see the latest development as a positive for Mr Joko, although Mr Wiranto cautions that the political reality in Indonesia is perennially fluid and control of Parliament in spirit may not necessarily translate into control of legislative flows.

"For Jokowi to push through necessary legislation, he would still need to negotiate on an issue-by-issue basis.

"So much will still depend on the implementation stage of policies on the ground at the end of the day."