Thai protest leaders turned down Prime Minister Yingluck Shinawatra's invitation for talks on Wednesday (January 15).
The government has decided to stick to an election date of February 2.
On the streets, a bid to shut down the capital is still underway.
Protesters have threatened to blockade the stock exchange and an air traffic communications facility if Yingluck does not step down.
Protest leader Suthep Thaugsuban has said he is not interested in an election and instead wants an unelected "people's council" that will enact reforms.
There are fears that the protests which have been peaceful so far, will turn violent. A shooting in an anti-government protest site early on Wednesday injured two protesters.
The unrest reflects an ongoing conflict between Thailand's middle class and royalist establishment and rural supporters of Yingluck and her brother, self-exiled Thaksin Shinawatra.