The joint parliament sitting on Thursday passed only one out of 13 constitutional change bills in the first reading.
The legislation would raise the number of constituency MPs from 350 to 400 and restore the old selection formula for 100 list MPs.
The bill was proposed by Democrat Party leader Jurin Laksanavisit, who is also a deputy prime minister and the commerce minister. It received 552 votes in favour, 24 against, 130 abstentions and 27 no-votes.
It proposed amendments to Sections 83 and 91.
Section 83 has 350 constituency MPs and 150 list MPs. The bill raises the number of constituency MPs to 400 and cuts the number of list MPs to 100.
For Section 91, the bill replaces the existing complicated formula to calculate the number of list MPs for parties with a previous and simple calculation method, basing the number of list MPs on the votes that a party receives from preferred-party ballots.
To pass the first reading, charter change bills needed a majority (at least 367 votes) of the combined membership of the House of Representatives and the Senate, with support from at least one-third of the senators, or 84.
Mr Jurin's bill was the only bill that met the criterion on senators' support, obtaining 210 votes in favour from senators, in addition to 342 votes from House representatives.
The parliament set up a committee consisting of 30 House representatives and 15 senators to scrutinise the bill within 15 days. The committee scheduled its first meeting for next Tuesday.
The other 12 bills will lapse.
