President Felipe Calderon has asked the Senate to scrap a commitment Mexico made when it signed the Pact of San Jose on Human Rights in 1981 to not take on the obligation of enacting legislation to protect life from conception.

The president's proposal to the Senate comes as the Supreme Court begins reviewing the constitutionality of reforms implemented in two states on the protection of life from conception, opening the way for the criminalization of abortion.

Calderon contends that a withdrawal from the Interpretive Declaration of the San Jose Pact would allow Mexico to endorse a "commitment to the right to life as a legal right protected under Mexican law," the Office of the President said in a statement.

The American Convention on Human Rights, also known as the Pact of San Jose, was adopted on Nov. 22, 1969, and holds that laws will generally protect the right to life from the time of conception and that no one will be deprived of life arbitrarily.

Mexico signed the treaty in 1981 with the provision that becoming a signatory "does not constitute an obligation to legislate to protect life" from conception and made it clear that "States reserve the right to have exceptions in their legislation, such as is the case with determining responsibility in abortion cases."

Calderon asked the Senate to take up the change in stance in accordance with the June 10 constitutional reforms, which recognize human rights protected in international treaties and the Mexican Constitution.

The Supreme Court on Monday began examining the constitutionality of reforms in the states of Baja California and San Luis Potosi that establish a right to life from conception.