Tomorrow's by-election in Bangkok's Constituency 6 is expected to be so closely contested that voter turnout could decide the result.
A victory for Kokaew could be interpreted as an indication that many Bangkok residents, or at least those in the constituency, agree with what the red shirts did, while a victory for Panich could point to support for the Democrat-led government.
The Democrats need to win this election to retain the seat formerly held by its MP Thiwa Ngernyuang, whose death from cancer necessitated the by-election at a time when every MP counts in key House of Representatives votes. But a slim margin of victory for the ruling party may be insufficiently convincing for Bangkok voters in the general election next year.
Election officials have noted concerns that the by-election is taking place at the start of the monsoon season and when there is a long public holiday.
Bangkok voters often opt to stay home rather than brave heavy rains to cast their ballots, and many residents prefer to spend a long holiday upcountry. Next Monday is a holiday for most businesses and Tuesday is a holiday for schools and state agencies.
However, the voter turnout of some 70 per cent in Constituency 6 was among the highest of the capital.
The chief of Bangkok's election office, Suthep Rommayanond, yesterday called on eligible voters to cast their ballots in the first half of the day to avoid possible downpours in the afternoon.
He said his office has prepared for heavy rains that could cause flooding at some polling stations in low-lying areas, although those places made up a small fraction of the more than 500 polling stations in the constituency.
The Bangkok election chief said he expected an unofficial election result by 8pm tomorrow.
The ruling Democrat Party and the opposition Pheu Thai Party yesterday separately held their final main campaign events for their candidates.
The Democrats campaigned for Panich at four locations in the constituency's four districts in the evening - the party's local office in Nong Chok district, a mosque in Klong Sam Wa, another mosque in Kanna Yao, and a school in Bueng Kum district.
Democrat Cabinet members and prominent figures addressed voters. They included Deputy Prime Minister Trairong Suwankhiri, Deputy Commerce Minister Alongkorn Ponlaboot, Agriculture Minister Theera Wongsamut, and former party leader Banyat Bantadtan.
However, while the Democrat candidate could freely conduct his campaigning, Kokaew has been detained at the Bangkok Remand Prison after failing to get court permission for temporary release to campaign outside.
Kokaew has been in remand along with other red-shirt leaders on the charge of terrorism in connection with the recent political unrest. He is Pheu Thai's second choice after another detained red-shirt leader, Natthawut Saikua, was found to have a qualification problem.
Pheu Thai held its final campaign events at Siam Park's parking area and four other locations late in the afternoon. They were attended by senior party figures including Chalerm Yoobamrung, Jatuporn Promphan, Vicharn Meenchainan, and Apiwan Wiriyachai, who is also a deputy Speaker of the House of Representatives. Many of the people attending the campaign events wore red.
During the Pheu Thai events, a four-minute video recording of Kokaew was played and a letter from him was read to the audience. He called on voters to elect him so that he could get bail and reunite with his family. His voice choked when he talked about his baby daughter.