A Thai court has refused to rule on the legality of the country's recent parliamentary election, dealing a blow to the opposition Democrat Party which said the vote was illegal.
The Constitutional Court on Wednesday also rejected a motion by the ruling Pheu Thai party claiming weeks of opposition protests represented an attempt to overthrow the state.
The rulings failed to break Thailand's political deadlock, which has gripped the country since late last year, leaving it with a crippled, caretaker government.
Prime Minister Yingluck Shinawatra had hoped the early polls on February 2 would end the crisis. But the opposition boycotted the election, and disrupted it in several provinces.
On Tuesday, the election commission said it will hold another round of polls in late April for areas where voting was unable to proceed. A specific date was not announced.
Until enough seats in the lower house of parliament are filled, a new government cannot be formed and Ms. Yingluck's caretaker government will have only limited control over policy.
The Pheu Thai Party is virtually assured to have won the vote, thanks in part to the boycott.
Opposition protesters say Yingluck is a puppet of Thaksin, the exiled ex-prime minister who was accused of corruption and overthrown in a military coup in 2006.
The opposition, meanwhile, has refused to end its rallies, despite the imposition of an emergency decree and warnings from government officials.
Authorities say arrest warrants have been issued for 19 leaders of the anti-government protests.
The protest movement is supported by many in the urban middle class who are angered by what they say is waste and corruption.
At least 10 people have been killed and scores hospitalized during the political upheaval.
Elections in Thailand
Soldiers hold their shields as officials leave a government office where Prime Minster Yingluck Shinawatra had been holding a meeting as anti-government protesters gather outside in Bangkok, Feb. 3, 2014.
An anti-government protester carrying a national flag, a guitar and a "No Vote" sign follows others moving from one protest camp to another in Bangkok Feb. 3, 2014.
Voters hold their identification cards and the chains that held the gate of the polling station closed, as they demand the right to vote during general elections in Bangkok, Feb. 2, 2014.
Anti-government protest leader Suthep Thaugsuban waves to supporters during a march through Bangkok, Feb. 3, 2014.
Thai Prime Minister and Pheu Thai party leader Yingluck Shinawatra poses before casting her ballot in Bangkok, Feb. 2, 2014.
Thai soldiers pose with their identity cards as they wait in a line to vote at a polling station in Bangkok, Feb. 2, 2014.
Empty ballot boxes are shown before voting in Bangkok, Feb. 2, 2014.
Anti-government protesters check voting ballots they seized to disrupt elections before handing the papers back to officials after the general election in Hat Yai district, Songkhla province, southern Thailand, Feb. 2, 2014.