Voters in Burma go to the polls shortly for by-elections that promise to be the most open contests in decades, with Aung San Suu Kyi among those standing.
Her National League for Democracy (NLD) is contesting all 45 seats, vacated when politicians joined the new, military-backed civilian government.
It is the first time Ms Aung San Suu Kyi is standing in an election herself.
It is also the first time international observers have been allowed to monitor elections in modern Burma.
The European Union looks set to ease some sanctions on the country if Sunday's elections go smoothly.
Ms Aung San Suu Kyi spent a total of 15 years under house arrest after the military overturned her party's landslide general election victory in 1990.
While only a fraction of seats are being decided, the NLD is expected to enter parliament as the official opposition.
With tens of thousands of people turning out to back Ms Aung San Suu Kyi and her fellow NLD candidates, the by-elections have taken on a huge significance, the BBC's Rachel Harvey in Burma reports.
Election officials in Rangoon and other parts of the country have been making final checks at polling stations, ensuring ballot boxes and booths are ready.
"We're preparing the election on 1 April to be free and fair," election official Maung Maung Than told the Associated Press news agency. "We'll make it free and fair, I believe this."
Ms Aung San Suu Kyi is standing for a lower house seat in the Kawhmu Township constituency outside Rangoon.
She arrived there on Saturday in a convoy of NLD cars, plastered with party stickers.
Small groups of people gathered to welcome her, wearing NLD T-shirts and waving party banners and portraits, AFP news agency reports.
The NLD boycotted the 2010 general election on the grounds that election laws were unfair.
Earlier, Ms Aung San Suu Kyi described this year's election campaign as not ''genuinely free and fair" but said she and her part did not regret taking part.
"Still we are determined to go forward because this is what our people want," she said.
At the same time, she warned that Burma's democratisation was "not irreversible".
A small number of representatives from the Association of South-East Asian Nations (Asean), along with the EU and US, have been invited to observe polling.
More than 100 foreign journalists are believed to have received permission to cover the vote.
EU Trade Commissioner Karel De Gucht said political sanctions on Burma were mostly "aimed towards individuals" and could be eased when EU foreign ministers met in Brussels on 23 April.
The lifting of such sanctions could "even happen with immediate effect", he told AFP on a visit to Phnom Penh, Cambodia.
"The European Union and also myself, I am excited by the prospect that finally, hopefully Myanmar citizens will get more freedom," Mr De Gucht added.
"Political freedoms and economic freedoms always go together."