Thailand's government has rejected a request from the election commission to postpone a February poll.
In a televised address on Thursday, the country's deputy prime minister said the February 2 general election would go ahead as planned.
The French News Agency says the deputy also said an election delay would cause more violence.
Prime Minister Yingluck Shinawatra had called for the early vote as a way out of a political crisis.
Protesters have been calling for the prime minister's removal, saying it is necessary to purge the country of corruption and money politics.
They view Ms. Yingluck as a puppet of her brother, former prime minister Thaksin Shinawatra.
The political crisis turned violent again earlier Thursday. Police fired tear gas and rubber bullets at demonstrators, who responded by throwing rocks.
Officials say one policeman was killed and dozens of protesters were hurt.
The clashes began after protesters ignored police warnings and stormed a sports stadium in Bangkok where officials were registering candidates for the scheduled February 2 vote.
Police spokesman Piya Uthayo said police came under fire during the clashes.
"I urge the people, especially those who convinced the protesters to use violence and to invade the building and to attack officers, please stop."
Weeks of feisty protests had forced Mrs. Yingluck to call for early elections and dissolve parliament, but she has refused to resign.
On Wednesday, Mrs. Yingluck proposed the creation of an independent national reform council that would work alongside the new government.
The protesters, led by ex-Deputy Prime Minister Suthep Thaugsuban, immediately rejected the proposal, saying reforms should be undertaken before any vote.
The main opposition Democrat Party has said it will boycott the election, which the prime minister's Pheu Thai Party was already predicted to win.
Former Prime Minister Thaksin, a billionaire businessman, was ousted in a 2006 military coup. He is living in self-imposed exile overseas after being convicted of corruption.
Ms. Yingluck and her brother have the support of Thailand's rural poor, largely because of Mr. Thaksin's policies to bring virtually free health care, cheap loans and other benefits to the long-neglected countryside. But they are disliked by the urban middle class and more educated elite.
Most of the protests, which at first aimed to occupy government buildings, have been peaceful, with police exercising restraint. However, earlier this month several people died in street clashes in the capital.