Uthai Yodmanee, coordinator of the Network of Students and People for Reform of Thailand (NSPRT), said the group will strengthen its non-violent activities to cancel the snap poll.
He charged caretaker Prime Minister Yingluck Shinawatra with attempting to exploit democracy for the benefit of her family’s businesses.
The group has set today as its deadline for the caretaker government to resign but Mr Uthai would not say if the group would seal off the Aeronautical Radio of Thailand and the stock market as threatened.
The main anti-government movement, the People's Democratic Reform Committee (PDRC), stood firm that the functioning of the two critical agencies will not be disturbed by protesters.
Mr Uthai said NSPRT will file a petition with the National Anti-Corruption Commission (NACC), charging caretaker Interior Minister Charupong Ruangsuwan and caretaker Education Minister Chaturon Chaisaeng with instigating Red Shirt activists during their speeches on stage at Rajamangala Stadium.
He said the pair appeared on stage on the same day as Ekapob Lue-ra, also known as Tang Acheeva, who made a libellous statement against the monarch and has been in hiding since.
Ms Yingluck may be involved in assisting Mr Ekapob, he alleged.
Mr Uthai said NSPRT called on police to report investigation developments in the murder of two protesters, Thaweesak Pohkaeo and Wasu Suchantabutr, and a guard, Yuthana Ong-art, in separate attacks on Nov 30, Dec 26 and 27.