Democrat MP Suthep Thaugsuban, a key leader of the party, led the protesters to march to the Temple of Emerald Buddha in the morning and reached the destination at noon.
Then, he announced to demonstrators that they would stay put at the Democracy Monument instead of returning to Samsen.
A party source said the party decided to shift to the Rajdamnone Road at the monument because the number of demonstrators was growing with support from many groups.
The party saw that the Samsen area would be too small to house the growing number of protesters.
The source said the growing number of demonstrators would make it difficult for police to use force to disperse them.
He added that the party saw that the area has many roads and sois so it would be difficult for police to besiege and round up protesters.