BANGKOK - Thai opposition Democrat Party's members of parliament on Sunday resolved to resign en masse to join the anti-government rally.

Democrat Party spokesman Chavanond Intarakomalsut said the party reached a unanimous decision to have all its MPs resign on Monday so that they could practically join protestors in a final showdown with the government of Prime Minister Yingluck Shinawatra.

Democrat Party leader and former premier Abhisit Vejjajiva said the Yingluck government is no longer "justified" to run the country and the Democrats will join Monday's final bid to eradicate the so-called "Thaksin regime" .

Former premier Thaksin Shinawatra, who is living in exile after being ousted in a 2006 coup, allegedly has influence on his sister Yingluck.

Earlier on November 11, nine Democrat MPs, including former vice premier Suthep Thaugsuban, resigned from the parliament to lead street protests.

Suthep is now secretary-general of the People's Democratic Reform Committee, an alliance of various anti-government groups. ?

Ahead of the final showdown, the police have started to erect barricades around major government buildings to deter protestors from occupying them.