JAKARTA (BLOOMBERG) - Indonesian President Joko Widodo may find himself without a challenger in the next election.

While General Prabowo Subianto - leader of the main opposition party and runner up in the 2014 election - has accepted his party's endorsement, it's uncertain if he can assemble a viable coalition to be nominated by an August deadline.

Mr Joko is leading in opinion polls and wooing the former general, who's seen as his only real competition.

The lack of a credible contender in next year's election would raise questions over Indonesia's young democracy, as well as Mr Joko's commitment to reforms.

He has recently faced criticism for distorting market mechanisms, risking a higher budget deficit and jeopardising much-needed foreign investment in South-east Asia's biggest economy.

"If Prabowo doesn't run, either because he can't secure the necessary support from other parties or because he makes an improbable alliance with the Jokowi camp, it would increase the likelihood of a one-horse race come April 2019," said Mr Hugo Brennan, a Jakarta-based senior Asia analyst at Verisk Maplecroft.

"Such a scenario would be a setback for Indonesia's still-young democracy."

Earlier in his term, Mr Joko, popularly known as Jokowi, undertook reforms that won him praise and secured Indonesia its all important sovereign ratings upgrades - paving the way for billions more in foreign investment.

In recent months, however, his government has intervened with price controls on staple foods and placed caps on coal input prices for electricity generation.

The distortions risk widening the budget deficit, said Mr Peter Mumford, South-east Asia director at Eurasia Group.

"The bigger risk for investors is the general intensification of economic nationalism," Mr Mumford said.

"His government is also planning protectionist measures on commodity shipping and insurance, which could further squeeze the role of foreign firms in the sector."

A party or coalition must have at least 20 per cent of seats in Parliament or have won a minimum 25 per cent of the popular vote in the last legislative election to nominate a candidate.

Mr Joko has secured the support of five of the 10 parties in Parliament, leaving Gen Prabowo's Gerindra - with 13 per cent of the seats - to secure support from the few parties left in order to get across the line.

The Prosperous Justice Party (7.1 per cent) and National Mandate Party (7.6 per cent) are the most likely partners for Gerindra.

But neither has declared their hand and could even support Mr Joko, who already has the backing of political heavyweights Golkar and PDI-P.

The National Mandate Party, known as PAN, remains undecided on a presidential nominee, according to its secretary general Eddy Soeparno.

Still, he said a scenario in which Mr Joko and Gen Prabowo teamed up wouldn't be good for the country.

"In the interest of maintaining a growing democracy, I think we should have a few candidates participating in the 2019 election," Mr Soeparno said in an interview in Jakarta on Monday (May 7).

It's unlikely the two will run on a combined ticket, he said, but if they do, "I don't think anyone would have the courage to challenge that combination."

Mr Joko has a commanding lead in the polls. A survey published April 23 showed him with 56 per cent support, compared with 14.1 per cent for Gen Prabowo.

Other potential candidates, including former president Susilo Bambang Yudhoyono's son Agus Yudhoyono, are barely blips on the radar.

The President has also reached out to Gen Prabowo, presenting the prospect of a unity ticket or power-sharing deal.

Lawmaker Fadli Zon, who is part the Gerindra team negotiating with other parties, said an "envoy" representing Mr Joko had approached him.

Gen Prabowo's brother, Mr Hashim Djojohadikusumo, made a similar claim in an interview in February.

"It's a bad idea," Mr Zon, who is also a deputy speaker with Indonesia's House of Representatives, said in an interview.

An election without a challenger indicates "there is no democracy", he added.

Independent political analyst Kevin O'Rourke said parties with seats in Parliament have been focused on patronage-style politics rather than pursuit of an ideological agenda or reform, leading to a "dearth" of potential presidential candidates.

"That's why there is a situation right now where Widodo is potentially unopposed as President," said Mr O'Rourke, author of Reformasi: The Struggle for Power in Post-Soeharto Indonesia.

Such an outcome would raise questions about "the health of Indonesia's democracy".