The party hosted by NLA chief Pornpet Vichitcholcha at the Army Club on Thursday night had no impact on their decision as most had already made up their mind, the observers said.
The NLA voted 190 to 18 to impeach Yingluck in her former position as prime minister.
Although she no longer holds the position, the NLA wanted the legal consequence to prohibit her from politics.
The majority who voted against Yingluck are mostly military officers who were installed by the junta.
Also seen as an enemy of Yingluck are a group of 40 former senators, while the 18 votes in her favour mostly came from people in the business sector.
The military-installed lawmakers mostly regard Yingluck’s handling of the rice-pledging scheme as a big mistake as she refused to end the project after the acknowledgement of corruption.
Yingluck delivered her opening and closing speeches at the impeachment proceedings but she did not answer any questions from NLA members. Some members gave her no credit for this.
In her speeches, Yingluck also did not answer any questions or clear up suspicions over the rice project.
She mostly attacked what she said was the National Anti-Corruption Commission’s political motive in impeaching her, a NLA member said.
The NACC’s decision to charge her former commerce minister Boonsong Teriyapirom and former deputy commerce minister Poom Saraphol for allegedly creating illegal government-to-government rice-sale deals confirmed Yingluck’s mishandling of the scheme, the NLA member said.
The NLA yesterday failed to impeach former Parliament president Somsak Kiartsuranon and his ex-deputy Nikom Wairatpanij in relation to an amendment of the 2007 Constitution.
As a consequence, the 38 former senators who sponsored the amendment bill also escaped impeachment.