A group of 66 lawmakers on Thursday filed a petition asking the Constitution Court to invalidate the 2-trillion-baht infrastructure development loans bill, reports said.
The group is made up of 55 senators led by Paiboon Nititawan, Sai Kangkawekin and Rossana Tositrakul and 11 Democrat Party MPs.
They handed their petition to Parliament President Somsak Kiatsuranon to forward to the Constitution Court.
The petition does not seek punitive action against individuals or political parties but asks the court to rule that the 2-trillion-baht loan bill contravenes Sections 169 and 170 of the constitution because it would allow spending outside the normal budgetary system.
The Democrat Party earlier filed a petition for the Constitution Court to rule on the legality of the bill after the legislation was passed in its third reading by the Senate early Wednesday.