Polls have closed in an Irish referendum on abortion that could represent a change in the path of a country that was once one of Europe’s more socially conservative.

Voters turned out in large numbers on Friday to have their say on whether to repeal the country’s Eighth Amendment, which outlaws abortion by giving equal rights to the unborn.

An exit poll, conducted for the Irish Times by Ipsos/MRBI, suggested that the country voted by a landslide margin to change the Constitution so that abortion can be legalised.

The vote to repeal the constitutional ban was predicted to win by 68 percent to 32 percent, according to the poll of 4,000 voters, the Irish Times said.

Polls closed at 21:00GMT.

The first indications of the final result are expected on Saturday, after the count begins at 08:00GMT.

Prime Minister Leo Varadkar, in favour of change, has called the referendum a “once in a generation decision”.

If the proposal to repeal the Eighth Amendment is defeated on Friday, the country will not have a second referendum and it could be another 35 years before voters have their say on the matter again, Varadkar said, according to the Irish Times.

Al Jazeera’s Neave Barker, reporting from the Irish capital, Dublin, said the vote has been contentious.

“The No camp believes they are defending the right of the unborn child, the Yes camp believe they are defending the right of a woman to make often a very difficult decision.”

Currently, 78 percent of the Irish population is Catholic, and members of the church are hoping their members will vote “no”.

Thousands of people living abroad returned home to vote. Ireland is one of the few countries in the European Union that does not allow those abroad to vote via post or in embassies.

Those away for less than 18 months remain eligible to vote at their former local polling station. Those living on the Atlantic islands cast their ballot a day early to help prevent delays in transportation and counting the ballot papers.

Below is what you need to know about the abortion referendum:

Eighth Amendment

First voted into the Irish constitution in 1983, the Eighth Amendment recognises the equal right to life of the unborn.

It says that “the state acknowledges the right to life of the unborn and, with due regard to the equal right to life of the mother, guarantees in its laws to respect, and, as far as practicable, by its laws to defend and vindicate that right.”

It is commonly viewed to equate the life of a pregnant woman with the foetus, effectively placing a ban on abortion.

When voted on, the referendum passed with 66.9 percent voting “yes,” and 33.1 percent voting “no”. About 1.2 million people vote.

Why the Eighth Amendment?

Abortion was illegal in Ireland under the Offences against the Person Act of 1861, but when contraception was legalised in 1974, there was concern from many conservatives that abortions would follow.

A campaign emerged and “pro-life” anti-abortion rights groups lobbied for constitutional protection of the “unborn”. A vote was held on September 7, 1983, which proposed adding an eighth amendment to the Constitution.

Ireland’s then-Attorney General Peter Sutherland warned at the time that the wording “will lead inevitably to confusion and uncertainty, not merely among the medical profession, to whom it has, of course, particular relevance, but also among lawyers and, more specifically, the judges who will have to interpret it.”

What does the law say today?

Two referendums took place in 1992, allowing women to travel to have an abortion, and another one authorising information about abortion services overseas.

In 2013, the law was changed to permit abortions when doctor felt a woman’s life might be at risk. But in other cases, a doctor can face prosecution and up to 14 years in jail.

Why is this vote happening now?

There have been a number of high-profile cases that have highlighted what critics say are problems with the current law.

Savita Halappanavar died in hospital in 2012 after being denied an abortion during a miscarriage, and in 2016, Amanda Mellet was forced to travel to England to terminate a pregnancy with a fatal foetal anomaly.

In 2016, the UN called on Ireland to reverse its strict prohibition, and for the first time, the Irish state compensated a woman for the trauma she suffered from having to go abroad for an abortion.

In 2017, the Irish government convened a Citizens Assembly to consider evidence on abortion law reform.

The 99 randomly selected citizens, after hearing extensive evidence, voted in favour (64 percent) of having no restrictions on termination in early pregnancy. The referendum was called earlier this year.

Who is opposed to the referendum?

Anti-abortion rights groups say they are protecting the foetus through their opposition. Many of these groups are supported from abroad, and they often align themselves with the Catholic Church.

Geraldine Martin, a spokeswoman for the Love Both anti-abortion rights campaign, said the government had failed to help mothers with unwanted pregnancies.

“At no stage has the government held out its hand to these women and said, ‘How can I help you? How can I take the pressure off you so you don’t feel so driven towards abortion?” she told AFP news agency.

What is the main argument to repeal it?

Many contend that criminalising abortion does not stop it. They argue a “yes” vote allows the government to legislate legal access to healthcare for women legally in Ireland.

“I’m very hopeful because I believe we have understood in Ireland that it [the ban] is a cruelty that must end now, we’ve had enough,” Ailbhe Smyth, the co-director of the Together for Yes pro-abortion rights campaign, told AFP news agency.

#HometoVote

In advance of the vote, the hashtag #HomeToVote trended on Twitter, with voters posting photos of both “yes” and “no”.

highly recommend scrolling through the #hometovote to see just how far some women have travelled for #repealthe8th – here are some from LA, Australia, Vietnam, Argentina. pic.twitter.com/Gql1tSXO3N — Rossalyn Warren (@RossalynWarren) May 24, 2018

https://twitter.com/theres_WALLY/status/999711428364906498?ref_src=twsrc^tfw