Small but vociferous protests have been held every day in the capital since the army seized power from the civilian government on May 22.
The protesters have succeeded in delaying the completion of an election called by Yingluck, undermining efforts to restore political stability.
Over, 2,00,000 police officers would be assigned to ensure security at 93,535 polling stations in 77 provinces.
Thailand’s prime minister has confirmed a general election will go ahead on Sunday despite a warning that it could end in chaos.
The protesters, who launched their anti-government campaign in November, have been demanding that Yingluck should step down and make way for an unelected “people’s council”.
Is it about the old establishment versus the new, populist challenger? Or about metropolitan conceit versus the aspirations of the rural masses?
Violent clashes take place near Yinglucks heavily fortified offices.
He told followers it would take another two days for their goal to be reached.