By Michael Buchanan
BBC News, Lisbon
High above the Tagus River overlooking Lisbon's majestic suspension bridge stands a statue of Christ, arms outstretched, looking down on the country's traditionally reverential citizens.
The image is a powerful symbol of the close relationship between the Catholic Church and the Portuguese people, but as the current debate over whether to legalise abortion is demonstrating, that bond is showing signs of strain.
Opinion polls are currently suggesting that a majority of people will vote on Sunday to allow a woman to have an abortion within the first 10 weeks of pregnancy.
The change is being pushed by the socialist government and by liberal activists.
Almirinda Bento: Abortion laws "shame" Portugal
Almirinda Bento, from the Umar women's rights group, says it is "unacceptable" that Portugal does not allow abortion.
"The state has to have a law that allows women to solve a problem that is in essence an issue of public health. The state should not leave women in such a state of fragility," she says.
Just because abortion is illegal here - except in cases of rape or where the woman or child's health is in danger - does not mean that thousands of women don't terminate their pregnancies each year.
The quickest and cheapest method - though also the most dangerous - is for a woman to take two pills that cause the foetus to abort.
Obtaining the drugs is extremely difficult for many women, and a large black market exists. In one example we heard about, nurses stole the pills from their hospitals, sold them to firemen, who then sold them on to pregnant women for about £100.
If a woman has a little more money, she heads to Spain. In the town of Badajoz, more than 4,000 Portuguese women have had abortions at the Clinica dos Arcos in the past two months alone. The clinic can perform up to 50 terminations per day and charges up to £400 for each operation.
The director of the clinic, Yolanda Hernandes, says: "We try to solve a problem for women that they can not solve in their own country. Women who reject maternity look for a way to get rid of the pregnancy.
"The only thing we can do is to offer women the best possible conditions. And dignity."
The journey to Spain is one that Carolina knows well. She was delighted when she found out she was pregnant - both she and her boyfriend had wanted a baby. But he changed his mind, and Carolina felt she couldn't bring up a child alone.
"To me, having a child is more than just giving it food or an education," she says.
"I saw myself suddenly unemployed, without the father to help. And I grew up without a father and for me that was very painful. I did not want to wish that on a child. Therefore I decided it was not the right time to have a child."
There have been strong campaigns waged on both sides
In Portugal women like Carolina can be sent to prison - for up to three years - for having an abortion.
Women in Malta also face jail terms in such cases. Abortion is also either banned or severely restricted in Ireland and Poland.
Several recent Portuguese court cases in which women were charged with terminating their pregnancies elicited widespread public sympathy. Pro-choice campaigners hope that the support can be turned into votes.
"It is a humiliation, a shame, for this country that women continue to be penalised," says Almirinda Bento.
The outcome of the referendum is, however, far from certain. Pro-life groups have waged a vociferous campaign and have closed the gap in several opinion polls.
The opposition to the proposed law change has been led by the Catholic Church, and they remain hopeful that when people walk into the voting booths, they will remember the Church's central message.
"Life is from the beginning to the end. If we give in and begin to consider that it is not really human life, if society, the state does not defend life - then where are we as a society going to end up?" asks Bishop Dom Carlos Azevedo plaintively.
The Church does more than condemn abortion however - it also helps women to have their children. Twenty-one-year-old Fatima found her herself in the same position as many young women - pregnant, alone, frightened and confused.
Yet she never considered abortion, she says, and had her child with the aid of the Church. "I had really hit the bottom. I had no-one to turn to. But even if we are desperate there is always someone to extend a helping hand as happened with me," she says.
Despite the heated opinions expressed by those people most involved in the abortion debate, there is a real concern on both sides that not enough people will vote on Sunday to make the referendum result binding.
If that happens, the government says it will attempt to legalise abortion through Parliament - if the "Yes" side gathers most votes.
But regardless of the referendum result, abortion may be coming to Portugal anyway. Yolanda Hernandes who runs the Clinica dos Arcos in Badajoz says she has found a weakness in the existing Portuguese law that will allow her to open a clinic in Lisbon in March.
"Those who do not want to have an abortion, do not have to. But those who do must have the best conditions possible. We must create the means," says Ms Hernandes.
To find out more about this story, watch the full report on www.bbc.co.uk/eorpa from 1930GMT on Thursday 8 February.