Channel 4 has banned an advertisement for abortion services from being broadcast in Northern Ireland.

Millions of viewers in England, Scotland and Wales will be able to watch the TV ad for Marie Stopes International (MSI) on Channel 4 at 10.10pm on Monday.

But the UK's fourth channel has been prevented from screening the commercial for MSI in Northern Ireland because abortion is still illegal in the province. Northern Ireland is the only part of the UK where the 1967 Abortion Act does not apply. All of the political parties in the Stormont assembly, except the Progressive Unionists, are opposed to the extension of the act to Northern Ireland.

Anti-abortion groups in Northern Ireland said they welcomed legislation blocking the ad from being broadcast, but they were angry that it would be screened elsewhere in the UK.

A leading sexual health charity based in Belfast said it was another example of how women in the province were treated differently to the rest of the UK.

The Family Planning Association said it highlighted the need to decriminalise abortion in Northern Ireland.

The ad, which is part of the 'Are you late?' campaign by MSI, will air on Channel 4 until the end of June.

Dana Hovig, MSI's chief executive, said: "It's a shame that we are not allowed to screen the commercial in Northern Ireland – abortion continues to be severely restricted there and women in Northern Ireland are forced to travel to England for abortion services.

"Therefore the advertising of abortion facilities, their contact numbers or addresses is against the law in Northern Ireland."

Dr Audrey Simpson, director of Northern Ireland for the Family Planning Association, said: "I think a lot of people would say it is inappropriate to use this ad on television because it would encourage women to have abortions.

"They use the argument that if you give people information it encourages them to go and do something. But women already have access to that information."