Mexico is poised to amend its constitution this weekend to require all judges to be elected as part of a judicial overhaul championed by the outgoing president but slammed by critics as a blow to the country’s rule of law.

The amendment passed Mexico’s Congress on Wednesday, and by Thursday it already had been ratified by the required majority of the country’s 32 state legislatures. President Andrés Manuel López Obrador said he would sign and publish the constitutional change on Sunday.

Legal experts and international observers have said the move could endanger Mexico’s democracy by stacking courts with judges loyal to the ruling Morena party, which has a strong grip on both Congress and the presidency after big electoral wins in June.