Issara Somchai, a former Democrat party-list MP and a native of Ubon Ratchathani province, said he has seen many northeastern people showing their support for the PDRC's bid to oust the caretaker government.
Mr Issara said thousands of anti-government protesters from the Northeast have been travelling to Bangkok since Jan 13 to join the PDRC's Bangkok shutdown campaign.
"Many of them have not returned home yet.
"They stay with me at the Lat Phrao stage to oust caretaker Prime Minister Yingluck Shinawatra and the caretaker government," he said.
Mr Issara said the PDRC protest is different from past anti-government rallies some years ago. Anti-government rally organisers in the past had to bring northeastern people to join political gatherings in Bangkok.
Those organisers also had to provide them with food and vehicles, he said.
"The PDRC's campaign is like a wake-up call for northeastern people. I believe many people from the Northeast are travelling to join the PDRC of their own accord," he said.
Mr Issara said he had spoken to many people from the Northeast, asking them why they decided to join the protest.
He said they had told him that they monitored the PDRC's campaign via the Democrat Party's BlueSky TV channel at home and believed the Pheu Thai government lacked transparency while administering the country.
The Bangkok Post found many northeastern people at the Lat Phrao stage were from Nakhon Phanom, Yasothon, Roi Et, Maha Sarakham and Udon Thani provinces.
They said they joined the PDRC protest in Bangkok without hesitation, when the lower House pushed through the blanket amnesty bill before dawn on Nov 1 last year.
They were also bored of corrupt politicians.
They said they felt they did not have freedom of speech in the northeastern provinces - the strongholds of red shirts and the Pheu Thai Party.
But the PDRC gives them a platform to express their opinions freely, they added.
They also said the government's rice-pledging scheme failure which caused delayed payments for farmers was another reason that drove them to join the PDRC movement.
"If we criticise or perform activities against the government, our houses may be attacked. State officials may not take legal action against the wrongdoers," said Sawang Chanchai, 66, an Udon Thani resident.
Mr Sawang said he feels state power does not protect those with different political views.
He said he joined the PDRC rally because he wants to see political reform in the country.
A 48-year-old anti-government protester from Uthai Thani, who declined to give her name, said she had witnessed the corruption of senior officers' during her position in a government office.
But she said she could not speak out about the matter because many officers have the support of red shirts.
She added that she could not wear a Thai flag shirt or criticise the Pheu Thai government because she might be targeted for harassment.
"Whatever happens to me, I don't care anymore. I want my home to be a better place," she said.