Her shiny black hair is sideswept and pinned back with white flowers, her salmon pink top contrasting brightly with the traditional black longyi pulled tight across her waist. With pamphlets in one hand and a bouquet of handpicked flowers in the other, she glides through the criss-crossed alleyways of fishmongers, vegetable sellers and betel-nut chewers on a hot afternoon days before the election, shaking hands, talking with locals and smiling at children.

There is no entourage surrounding her, no crowds vying for a glimpse of – or photo with – the so-called living saint, because this is not Aung San Suu Kyi but another, far less well-known opposition candidate: Khin Pyu Pyu Nyein, of Burma's National Democratic Force (NDF).

The 37-year-old is a self-made businesswoman who, unlike her near-doppelganger, is unlikely to win the seat she is contesting in Sunday's byelection. With only her own personal savings to dip into for funding and a handful of ardent, bamboo-hatted campaigners on the trail to support her, Khin Pyu Pyu Nyein is running against both the government-backed Union Solidarity and Development party (USDP) and Aung San Suu Kyi's National League for Democracy (NLD) for a seat in the Rangoon township Mayanqon.

After losing to the USDP in 2010 in elections that she contests were unfair, Khin Pyu Pyu Nyein now says her real challenge will be beating the NLD in an election that many argue could make or break Burma's apparent move towards democratic reforms. "But whether I win or lose doesn't matter," she says. "What matters is a different future for Burma."

Foreign media have all but declared the byelections – for 45 seats in Burma's 664-seat national parliament – a triumphant moment for Burma's opposition. But Khin Pyu Pyu Nyein's efforts represent a different view of the campaign trail in Burma, that of a splintered opposition force where parties lacking the funds of the USDP or the fame of the NLD are nonetheless fighting for greater freedoms too.

"The NLD has big cars to campaign with and Aung San Suu Kyi T-shirts to make money from," said the NDF's Khin Maung Swe, a former political prisoner who spent 16 years in jail before running and losing in the 2010 elections. "Look at us, look at me: I am no Aung San Suu Kyi. We have no funds, only spirit. We are pitiful."

The NDF is a splinter group that broke off from the NLD two years ago when Aung San Suu Kyi's party refused to participate in the elections and was temporarily banned. The NDF chose to run to "continue the struggle for democracy", Khin Maung Swe said, but it has since been branded "political traitors" by the NLD – hence the little chance of reunification, despite their similar platforms.

"We met Aung San Suu Kyi twice and shared some thoughts on politics, but she did not discuss the possibility of a [shared] political future," said Khin Maung Swe, who in 1988 was handpicked by Suu Kyi to work in the NLD's central committee. "That means she wants to go by herself – and that is one of [Burma's] main obstacles, because NLD cannot win all of the seats … There's no chance to win [alone] all the constituencies … unless we form an alliance."

At a news conference on Friday on the lawn in front of her lakeside villa in Rangoon, Aung San Suu Kyi referred to the possibility of working with other opposition groups in the future, but did not elaborate on creating an alliance.

The NDF knows it will not be easy to win all 13 seats it is contesting in the byelections, in what many hope will finally be a democratic shakeup in a country ruled for half a century by repressive military juntas. Change may be a word on everyone's lips, but just how much – and how soon – it will occur is still anyone's guess.

Some question the political knowhow of the NLD, which is contesting 44 seats and is expected to win a good number of them. Critics say it is a party that has long stood in the shadows waiting for its moment to rule, and that it is all well and good to be a hero – as many consider Aung San Suu Kyi to be – but the moniker alone is insufficient to run a country.

"Daw Suu plays an important role in the democratisation and modernisation of this country, but she alone can't do it," said Khaw Zyaw Mint, 30, a doctor based in Rangoon. "That's why she must train a new generation of politicians to replace her when she is gone. Right now, there is no one else to replace her, and no major political party should be [vulnerable] like that."

Others say that it is not just Aung San Suu Kyi who is at risk but also the president, Thein Sein, who has ushered in a slew of reforms since taking office in November 2010 – among them freeing political prisoners, relaxing censorship laws and allowing the NLD to run for election.

"There has been improvement in Burma, and that is of course welcome," said Win Myo Thu, whose Rangoon-based nongovernmental organisation Eco-DEV has been monitoring the election. "But these changes are based on [the actions of] individual persons who are trying to make change, like President Thein Sein and Aung San Suu Kyi. So if they are suddenly gone, the change they brought is also gone. That's a danger. We have been very divided in the past and that's why it's important to create a process right now … We have to look carefully at how splits can lead to negative directions."

In a nation where the military makes up a quarter of the parliament, the threat of a sudden stop to the recent advancements towards democracy is real. Even Aung San Suu Kyi has warned repeatedly that, although she trusts Thein Shein and his "genuine wishes for democratic reform", she is unsure how much military support he has.

Sein Win, a once-exiled Burmese journalist who resettled in Rangoon in January, said this threat had allowed opposition groups such as the NLD and NDF to gain clout with the populace — and their time may finally have come.

"The Burmese government has never answered to its people, it's never provided accountability," he said. "Instead it's provided a master and slave relationship. So many people have a hatred against the government, and whoever is against the government is [considered] a hero. That's why in Burmese politics you need a sacrifice – and the barometer is how many years you spent in prison."

By that measurement alone it is easy to see how Khin Pyu Pyu Nyein, who has never been imprisoned, could lose out to a party headed by Aung San Suu Kyi, who spent the greater part of the past 22 years under house arrest. But whether such a barometer will hold true come Sunday, only Burma will decide.

• Esmer Golluoglu is a pseudonym for a journalist working in Rangoon



• This article was amended on 1 April 2012. In the original, Win Myo Thu's name was wrongly given as Myu Zaw Win. This has been corrected.