BANGKOK — Thailand’s Constitutional Court nullified last month’s general election on Friday, forcing new polls and aggravating a political crisis in which protesters have occupied parts of the capital for four months to demand the government yield power to an interim appointed council.
The judges voted, 6 to 3, to declare the Feb. 2 election unconstitutional because voting was not held on the same day in 28 constituencies where protesters prevented candidates from registering. The constitution says the election should be held on the same day nationwide, although it also allows for advance voting.
‘‘The process is to have a new general election,’’ Pimol Thampitakpong, the court’s secretary general, said in announcing the decision.
Caretaker Prime Minister Yingluck Shinawatra has refused the protesters’ demands that she resign, and called early elections to receive a fresh mandate. The protesters attempted to prevent the election from taking place, physically blocking and intimidating candidates and voters.
Yingluck’s Pheu Thai party and its predecessors have won every national election since 2001. It was expected to win again in February, especially because the opposition Democrat Party boycotted the election.
Yingluck’s standing as caretaker prime minister was unaffected by Friday’s ruling.
Election Commission president Supachai Somcharoen said it would take at least three months for a new election to be held. In 2006, there was an eight-month gap before rescheduled polls were to be held after an election was nullified, but the army carried out a coup before they could take place.
Thailand has suffered from political conflict since Prime Minister Thaksin Shinawatra, Yingluck’s brother, was ousted in the 2006 coup after being accused of corruption and abuse of power. Thaksin’s supporters and opponents have since taken to the streets for extended periods in a power struggle.
The latest protests have kept the government, already limited by its caretaker status, from carrying out any major policy initiatives. The protesters have blockaded and sometime occupied government offices in the capital.
Supachai, the election commissioner, said he was not worried that the protesters would block a new election.
‘‘Times have changed and so has the situation,’’ he said, without further explanation. He urged people to love their country and work to help it.
‘‘If there’s a new election, the country can then move forward,’’ he said. But he added that ‘‘if the situation is still intense, then we should not hold the election because it will be a waste of people’s tax money.’’