SANTIAGO, Chile -- Chileans head to the polls on Sunday to vote on whether or not to accept a new constitution to replace the one in use since the Augusto Pinochet dictatorship (1973-1990).

Here, AFP looks at the most striking differences between the old and new 388-article constitution.

Political system

The new constitution describes Chile as a social democratic state of law and proposes a change to the existing bicameral congress.

Currently the senate is tasked with "perfecting" the work of the chamber of deputies.

The new constitution envisages disbanding the senate and replacing it with a chamber of the regions.

It would be an "asymmetric" congress with a more powerful chamber of deputies that would create laws and a body representing the regions that will only oversee certain relevant bills.

Detractors fear this would strip parliament of some of its powers and leave too much in the hands of the president.

In the new constitution, women would be guaranteed at least 50 percent of the positions in state institutions.

The new constitution recognizes the rights of nature and animals and protects water sources -- which are currently privately owned, often by big mining companies -- as a human right.

The old constitution bars the state from taking part in business activities, but the new one would oblige it to provide goods and services to meet the people's basic needs.

Health and pensions

The new constitution proposes a universal health system in which everyone pays compulsory contributions into the public purse.

As things stand, people can choose to make those payments to private health institutions.

Instead, with all contributions paid into the public health system, individuals who want -- and can afford -- private healthcare would then have to separately purchase private health insurance. At the moment, just 16 percent of the country benefits from private healthcare.

The new constitution would also require both employees and employers to pay into Chile's social security system, whereas only employees currently pay into it.

Abortion

The current constitution protects "the life of the unborn," although a 2017 amendment decriminalized abortion in three specific cases.

The new constitution includes the right to "voluntary abortion," although the exact specifics, such as the gestational time limit, would have to be set by congress.

Simply guaranteeing the right to abortion in the constitution would however set Chile apart as one of the few countries in the world, and the only one in Latin America, to do so.

Indigenous rights

The old constitution does not mention Indigenous people, who make up almost 13 percent of Chile's population.

The new text would recognize 11 Indigenous groups and acknowledge different nations living within the same country, although the state itself would remain "unique and indivisible."

One of the most controversial new clauses, and one that is motivating many Chileans to reject the new proposition, would grant greater self-rule to Indigenous people and recognize their own courts, as long as they respect the constitution and international treaties. The supreme court would also retain supremacy over Indigenous courts.

Housing

Chile's population of 19 million currently faces a deficit of half a million homes that has been growing since 2015, according to the state pollster Casen.

The new constitution would make housing a right, meaning congress would need to find ways to make up the shortfall with affordable housing.

It also guarantees the right to dignified and appropriate accommodation that would require all social housing be built to certain specifications.

Currently, real estate companies build vertical ghettos of massive apartment blocks with narrow homes that are rife with overcrowding.