Somsak Kosaisuk, right, a leader of the People’s Alliance for Democracy, submits an urgent petition to the Central Administrative Court seeking an order to suspend the release of voting results pending litigation against the Election Commission.

Thai voters were sharply divided by region when they went to Sunday's polls, according to unofficial election results available yesterday.

Although candidates from the ruling Thai Rak Thai Party were emerging victorious in most of the 400 constituencies, it was not an easy win for them.

They had to fight against the unusually high amount of abstention votes in many areas, including Bangkok and the southern provinces, while Thai Rak Thai candidates running unopposed in 278 constituencies had to garner a minimum of 20-per-cent support.

The number of "protest" votes was unusually high, even in many constituencies regarded as strongholds of the ruling party.

Thai Rak Thai faced only small obstacles in most northern and northeastern provinces, the traditional support base for the party.

However, in inner-city constituencies of some provinces in these regions, such as Kamphaeng Phet, Nakhon Ratchasima, Nakhon Sawan and Nong Bua Lamphu, the number of "no vote" (abstention) ballots exceeded the number of votes cast for Thai Rak Thai candidates.

No official election result had been declared as of last night.

In the Central region, voters were divided between those supporting Thai Rak Thai and those casting abstention votes.

In six of the eight constituencies in Chon Buri, where the ruling party grabbed all the seats in the previous election last February, the number of abstention votes was greater than that those cast in favour of the Thai Rak Thai candidates.

What surprised political pundits was the ruling party's victory in Sa Kaew, the traditional stronghold of Snoh Thienthong, who left Thai Rak Thai recently in a not-so-amicable farewell. Thai Rak Thai candidates won by wide margins, with their votes far outnumbering the abstention votes.

At least 38 constituencies in 15 provinces, mostly in the South, will see by-elections after the Thai Rak Thai candidates running unopposed failed to get votes from at least 20 per cent of the eligible voters, Election Commission secretary-general Ekkachai Warunprapha said yesterday.

The provinces are Krabi (three constituencies), Chumphon (2), Trang (3), Nakhon Si Thammarat (5), Narathiwat (3), Prachuap Khiri Khan (1), Pattani (2), Phang Nga (1), Phatthalung (2), Phuket (2), Yala (2), Songkhla (7), Satun (1), Surat Thani (3) and Phetchaburi (1).