The Thai government has rejected a call to postpone a general election due to be held on 2 February.
The Electoral Commission urged a postponement over safety fears for candidates on the campaign trail.
But government officials said parliament was already dissolved so there was no legal reason for a delay.
protesters want the government to stand down and be replaced by an unelected "people's council".
In a televised address, Deputy Prime Minister Phongthep Thepkanjana rejected the electoral commission's request.
"The Election Commission said holding elections will bring violence but the government believes delaying an election will cause more violence," he said on Thursday.
The BBC reports demonstrators have dismissed the election and the official opposition has refused to field candidates.
Protesters have also rejected another offer by Prime Minister Yingluck Shinawatra to form a national reform council.
The Pheu Thai Party led by Ms Yingluck won the last election in 2011 and has a big majority in parliament.
However, protesters claim her brother controls the government from self-imposed exile. Thaksin Shinawatra was overthrown in a military coup in 2006.