Website www.tpd.in.th said that while there were 13 parliamentary meetings and 32 vote counts in May, Yingluck cast ballots in just 9.4 per cent of those matters.
Among the 26 MPs who failed to vote in parliamentary meetings in May, 17 were Democrats, five were from Pheu Thai, three from Bhum Jai Thai and one from Chart Thai Pattana.
Education Minister Suchart Tadathamrongvej and Democrat Party secretary-general Chalermchai Sri-on cast a vote in just over 3 per cent of matters while Commerce Minister Boonsong Teriyapirom voted in just over 6 per cent.
MPs who failed to vote in May included Bhum Jai Thai's Boonjong Wongtrairat, Democrats Panyawat Boonmee and Picharnmet Muangmanee and Pheu Thai's Sataporn Maneerat. The House secretariat said they had reported leave of absence.
MPs who attended less than a third of the total meetings in May were Chart Thai Pattana's Sanan Kachornprasart and Democrat Sorawut Nerngchamnong.