MEXICO CITY (Reuters) - Mexico’s lower house of Congress on Thursday approved changes to the constitution to eliminate immunity from prosecution for all public servants, including lawmakers and the president, a move meant to tackle deeply entrenched corruption.

The resolution, which must still be approved by the Senate and ratified by a majority of state legislatures, modifies and repeals various provisions of eight constitutional articles.

A sitting president can currently be put on trial only for treason and “serious crimes of the common order.” The constitutional changes would remove those restrictions and also establish that defamation, libel and slander cannot be punishable with jail.

“This will be historic for Mexico because we have finally decided to eliminate immunity for all public servants, from the President of the Republic to the governors, legislators, the judiciary,” said congressman Marko Cortes Mendoza of the center-right National Action Party (PAN).

The move to strip public servants of immunity comes ahead of the July 1 presidential election, as candidates have pledged to transform Mexico’s corrupt political system.

There were a record number of killings in Mexico last year as organized crime gangs smuggled drugs, fuel and people while corruption scandals hit the credibility of President Enrique Pena Nieto’s Institutional Revolutionary Party (PRI).

Presidential hopeful Jose Antonio Meade of the ruling PRI party, currently running third in polls, has argued that nobody in Mexico should be above the law, not even the president.

Meade said last month he would ask lawmakers to present a bill to eliminate political immunity.