HARRISBURG — State representatives began Monday to debate whether their own ranks should be thinned by about one-quarter.

The House took up a bill, sponsored by the speaker, to cut the chamber from 203 members to 153. The first amendment, which passed overwhelmingly, also would reduce the Senate by the same proportion, from 50 to 38.

The proposal is a constitutional amendment that requires passage by the Legislature during consecutive two-year sessions and approval by state voters.

“It will make this legislative body more effective in the sense of producing quality products out of the end of the legislative manufacturing line,” said the sponsor, Speaker Sam Smith, R-Jefferson.

The House also rejected an amendment that would have cut the Senate more deeply, to 30 members.

“It’s become apparent to me that the Senate is probably open to a proportionate reduction,” Smith said. “Whether they would agree with 153 and 40, I don’t know for sure.”

Smith defended the 50-member reduction against those who have argued it might reduce the clout of rural districts or areas home to concentrations of racial minority voters.

The House voted overwhelmingly against a proposal by Minority Whip Mike Hanna, D-Clinton, to replace the current system with a unicameral Legislature of 407 districts that would only meet in January, February, June and July.

“It shifts power wildly, not just a little bit, I think it shifts it wildly to the executive branch of government,” said Smith, before voting with 161 other members to defeat Hanna’s amendment. Thirty-two members, including seven Republicans, voted yes on the part-time, single-chamber proposal.

Monday’s session ended before all amendments had been considered, with dozens more still pending.

The soonest the bill could see a vote on final House passage is Wednesday.