Issara Somchai, a People's Democratic Reform Committee (PDRC) co-leader who is supervising a rally site at Lat Phrao intersection, made the announcement on Sunday evening.
The move was aimed at ensuring better safety for the protesters after the two rally sites were attacked by gun and bomb attacks last month.
Mr Issara said PDRC secretary-general Suthep Thaugsuban would go to pick up the protesters at Lat Phrao at 9am. They will march to Victory Monument and carry on to join other demonstrators at Lumpini Park, using Phaholyothin Road.
Monk Luang Pu Buddha Issara still leads a protest on Chaeng Wattana road, where the protesters were also attacked by gunmen.
Mr Suthep will ask Luang Pu to close the Chaeng Wattana protest venue and move to Lumpini Park. But if Luang Pu insists on staying there, Mr Suthep will not force the issue, Mr Issara said.