It is a sign of how far Myanmar has come with political reforms that the gathering, which runs through Sunday in Yangon, is allowed at all. It's also a test for the National League for Democracy, which is working to transform itself from a party of one into a structurally viable political opposition in time for national elections in 2015.
NLD officials hope the first all-party congress will make the structure and operations of the party more reflective of its democratic ideals and infuse its aging ranks with youth, diversity and new expertise.
"Our party must be renewed and reformed," said Tin Oo, 86, who helped found the NLD and is overseeing the organization of the all-party congress. "We are going to advocate for democracy, so our party must be based on democratization."
Forged under authoritarian rule, the NLD has been, in some ways, a mirror image of the country's ruling Union Solidarity and Development Party. Unable to convene party meetings, with its leaders often jailed and the party itself officially banned for much of its existence, the NLD could not hold elections. Leaders had to be appointed. Secret and summary decisions had to be made. And in the unforgiving narrative of repression which has long governed Myanmar there were heroes who were not to be questioned any more than the villains they fought.
"Our party was a democratic party and the party was run by people not elected but selected; individuals like myself and Aung San Suu Kyi," said Win Tin, 83, a journalist and one of the NLD's three surviving founders.
In November 1988, within two months of the NLD's founding, the party's top leadership began planning an all-party congress to elect local and national level leaders, but was only able to hold a few township elections.
"Then all of us were sent to jail and kept there for a long time," said Win Tin.
On Friday morning, representatives from across the country stood in neat lines outside the Taw Win restaurant, waiting to be screened for entry. Above them a row of red NLD party flags, decorated with yellow fighting peacocks, fluttered in the early light. The mood was ebullient and hopeful, as people greeted old friends and colleagues.
"I am very excited to be here," said Nan, a 46-year old from a ruby-rich area of the northern Mandalay region, who goes by one name. "This is a step in the right direction and we hope to see the NLD transforming into a more democratic structure, in line with the changes taking place in the country."
In addition to electing leadership committees and a party chairman at the congress, the party aims to decide on a coherent policy platform this weekend. Win Tin hopes a new, younger generation of leaders who better reflect the country's ethnic diversity will emerge.
"At least we will have picked some people capable of leadership," he said. "We hope. We don't know yet."
The structure of democracy is one thing, its culture another. Most members of the NLD, like the people of Myanmar itself, understand the contours of democracy only through its absence. This lack of a developed political culture, some party members say, contributed to infighting and irregularities that marred some of the more than 17,000 local elections the party has convened since mid-2012 in preparation for the congress.
The years of repression and Suu Kyi's unique, iconic stature—she is greeted by villagers with cries of "Long live mother!"—have also centralized decision-making, which critics say is bad for the broader project of democracy in the country and could weaken the NLD in upcoming elections.
"All the party decisions are dependent on just Daw Aung San Suu Kyi and became a burden to her," said Yan Myo Thein, a 43-year-old former student activist and political analyst, who is not a member of the NLD. "The decisions are made only by one person and this is bad for the future of the country and the country's reforms. If the party goes on like this, the support of the people on NLD will waver."
These days, the tables outside the NLD's Yangon headquarters are littered with the junk of celebrity. There are Aung San Suu Kyi mugs, key chains, postcards, posters, photos, pins, fans and even a few corporate day planners. All are for sale.
Inside, the tight, two-story space is plastered with her image—ever beautiful and poised—and that of her father, General Aung San, who is regarded as the founder of independent Myanmar.
One could be forgiven for mistaking the place a shrine, except for the general dishevelment and buzz of activity.
Some argue that the NLD needs a single, strong leader in order to tackle their formidable opponents from the ruling USDP party—men who come from the military and understand the power of hierarchy and loyalty—but others fear that the party is not currently strong enough to survive without Suu Kyi.
Phyu Phyu Thin, an HIV activist and an NLD parliamentarian, doesn't want to speculate on a future without her.
"We pray for her good health," she said.