The United Front for Democracy Against Dictatorship, whose members are called the Red Shirts, backed former Prime Minister Thaksin Shinawatra, now in exile after being ousted in a coup and charged with corruption. The People's Alliance for Democracy, or Yellow Shirts, supported the coup.
After a meeting Thursday, leaders of the groups said one proposal calls for a bill to grant amnesty to those facing criminal charges from rallies between 2006 and 2011, the Bangkok Post reported. Another bill would set up a procedure to consider amnesty for others on a case-by-case basis.
Shinawatra's sister, Yingluck Shinawatra, now heads a coalition government.
Korkaew Pikulthong, a United Front leader who now sits in Parliament representing the Pheu Thai Party, said no decision has been made about Thaksin Shinawatra, who might be excluded from any amnesty. The bills would have to be presented to Parliament.