A pro-choice charity that for decades has helped thousands of Irish women access abortions in England is sending foreign nationals to the Netherlands due to tighter UK visa regulations and the effects of Brexit.

The Abortion Support Network (ASN) said it was guiding immigrant women in Ireland towards Dutch abortion facilities because it was taking too long to obtain visas for English clinics.

The London-based organisation also warned that even EU citizens living in the republic may have to travel to Holland for terminations after Brexit rather than crossing the Irish Sea.

ASN saidit was focusing on helping women from Ireland who were more than 12 weeks into a crisis pregnancy – the new legal limit for terminations in Ireland, which was introduced after the historic 2018 referendum to introduce abortion into the state.

One of ASN’s principal concerns is for immigrant women such as a young African girl who became pregnant after being raped by soldiers in a civil war and made her way to Ireland. In 2014, she was refused an abortion in Ireland and forced to go through with the pregnancy by caesarean section in an Irish hospital.

Other examples include a refugee who was pregnant when she arrived in Ireland but was afraid to tell anyone until she was 17 weeks. She spoke no English and had little support from the few people she knew in Ireland. Despite efforts to help her, the client was unable to travel to get an abortion before she reached the legal limit in Amsterdam. So she was forced to continue her pregnancy because ASN could not get her a visa to the UK in time.

Mara Clarke, ASN’s director, told the Guardian it had noticed that since the Brexit vote and the Irish abortion referendum it was getting harder to obtain visas for these women to travel from Ireland to Britain.

“For the past two years we’ve been finding it more and more difficult for non-EU residents of Ireland to get visas into the UK. And bear in mind that a ‘non-EU resident’ can be defined as anyone from an asylum seeker to a student from South Africa.

“We’ve found it easier for those people to go to clinics in Holland where they go to 22 weeks and five days.”

Clarke said many of their cases dealing with non-Irish women needing abortions beyond 12 weeks had been dogged by visa delays.

“We had one case where a client was turned down five months after applying for a visa into the UK. There was another case where the UK part of the visa was approved a day and a half before the Irish part expired, so we had to pull in favours to get the client an appointment in an English clinic as well as paying a premium for last-minute flights.”

Clarke said that after consulting with organisations representing immigrants in Ireland ASN decided it would be easier to send clients to the Netherlands.

“This means it is no longer possible for the woman to take the trip in one day but it’s better than nothing. I want to make clear that our only issue is with the UK visa process, not with the UK clinics,” Clarke said.

She warned that when Britain finally leaves the EU this could have major implications, even for European citizens who live in the Irish Republic. Irish citizens will have a special right to travel to Britain unhindered under the Ireland-UK Common Travel Area agreement between the two states. However, this will not apply to other EU citizens.

Explaining why Dutch clinics may be ASN clients’ best option after Brexit, Clarke said: “Any Brexit impact on travel – whether it is people needing a passport that is valid for a certain amount of time, or people needing visas or other travel documentation – will impact on people travelling for abortion. Even extra delays at airport security post-Brexit could mean people travelling from Ireland to England would be forced to stay overnight at clinics instead of coming in and out in one day.”

Over the last five years, ASN has helped 681 women from Northern Ireland, 53 from the Isle of Man and 2,605 from the Irish Republic to have terminations at clinics in England. The group has given 975 clients £298,741 in financial support to pay for abortions in the same period in English clinics.

The Irish Refugee Council (IRC) in Dublin said delays in treating non-Irish women who were in crisis pregnancies made it more likely they would have to travel abroad for an abortion.

Nick Henderson, the IRC’s chief executive said: “In the experience of the Irish Refugee Council, particularly for a person who is the victim of sexual violence, it can be very difficult to disclose their experience and that they might be pregnant. This can cause a delay for people newly arriving in the jurisdiction and they may be well outside the 12 weeks before they seek help. With each delay it becomes more likely that a person seeking asylum will need to travel for an abortion.”