He resigned his seat in Parliament in November 2013 to become the self-appointed Secretary-general of the People's Democratic Reform Committee, which was conducting mass protests trying to unseat the government of Prime Minister Yingluck Shinawatra.

When the government of Pheu Thai Party-leader Yingluck Shinawatra took office on 9 August 2011, his term as deputy prime minister ended.

Suthep addressed a huge crowd in his Surat Thani constituency a month before a no-confidence debate and called on his supporters to march on Bangkok in the hundreds of thousands to defend his reputation.

[15] The scandal led Prime Minister Chuan Leekpai of the Democrat Party to dissolve the House of Representatives in July 1995 in order to avoid the no-confidence debate.

[16] In subsequent elections, Thai Nation Party won a majority, leading to the downfall of Chuan Leekpai's Democrat Party-led government.

Under the 1997 Constitution of Thailand, which Suthep had supported, Members of Parliament are banned from holding stakes in companies which have received government concessions.

[20] After several Criminal court rulings that deaths and injuries sustained by Red-Shirt protesters during the political unrest in April and May 2010 were the direct result of orders to soldiers given by Suthep Thaugsuban, the director of the Resolution of the Emergency Situation (CRES), the Department of Special Investigation, public prosecutors and police agreed to file murder charges against him.

[23][24] Suthep was the most prominent leader of the anti-government protests that started in late October 2013, triggered by a government's proposal for an amnesty bill.

[29][30][31] After the coup d'état of 22 May 2014 led by army chief Prayut Chan-o-cha, Suthep like other leaders of the two rivaling political camps was detained by the military for a few days.

[33] He took the monastic name of Prapakaro and took up abode at the Suan Mokkh meditation centre in Chaiya District (Surat Thani Province).