Starting his career as a journalist, he later founded "Manager Daily" newspaper as well as satellite broadcaster ASTV. Originally a strong supporter of former Prime Minister Thaksin Shinawatra, he later became a leader of the anti-Thaksin movement. Under his leadership, the PAD was the major player in the 2005–2006 Thai political crisis that led to the 2006 military coup that toppled the Thaksin government. When Thaksin-affiliated parties won the 2007 general election, Sondhi became the major player in the 2008–2009 Thai political crisis, leading the PAD in violent clashes with security forces and anti-PAD protestors as well as the seizure of Government House, Don Muang Airport, and Suvarnabhumi Airport. Sondhi is more or less a supporter of the Democrat Party and stopped the PAD's protests after Democrat leader Abhisit Vejjajiva was appointed Prime Minister.