Northern Ireland, as I’m sure you know, isn’t a Catholic country. If anything, the Protestants (especially the disproportionately influential Free Presbyterian Church of Ulster) probably bear more responsibility for keeping abortion illegal in Northern Ireland than the Catholics do. Sinn Féin, which has traditionally gained the most support from Catholic voters, actually favours liberalising the law on abortion. The smaller Social Democratic and Labour Party, which also has traditionally been mainly supported by Catholic voters (though also some Protestant nationalists), is officially pro-life, but has recently decided to allow its members a free vote should the matter ever be put to the Northern Ireland Assembly.
Of course, there now hasn’t actually been a Northern Ireland Assembly for almost a year and eight months, so it’s currently unclear how the issue is going to proceed. There’s quite strong support in Great Britain for the idea of having the Northern Ireland abortion law reformed by the United Kingdom Parliament. Personally, I think that as it’s a devolved issue we should wait until the Northern Ireland assembly can be reconvened (assuming that it will ever be reconvened) and allow Northern Irish legislators to make the decision for themselves. Of course, one of the reasons people in Great Britain favour the UK imposing legislation on Northern Ireland during the ongoing suspension of the Assembly is because Northern Ireland is so massively out of step with the rest of the UK on this issue. Given the sensitivity of the issue and the strength of feelings on both sides, it would seem dangerous for the UK Parliament to legislate opportunistically on a devolved issue during the suspension. Given that opposition to abortion is now actually stronger within the Unionist/Loyalist community, we could witness the not unprecedented situation of Ulster Unionists/Loyalists instigating violent protests against the government of the very country to which they purportedly feel such a strong attachment with potentially disastrous consequences for whole of Northern Ireland.
Furthermore, one has to consider the present circumstance that the Conservative government is a minority government and can only govern with support from 10 MPs from the staunchly pro-life Democratic Unionist Party. If the government introduced legislation to liberalise abortion in Northern Ireland the DUP could potentially bring down the government and even prompt yet another general election before Brexit is concluded. I guess there’s no reason why a backbench MP, perhaps from an opposition party, couldn’t introduce the legislation. After all, there is a tradition of controversial legislation being introduced by backbenchers. It also complicates matters further that the seven Sinn Féin MPs don’t take their seats, meaning that seven out of 18 Northern Irish constituencies have no representation in Parliament (but would have representation in the Assembly, since Sinn Féin members do take their seats there). So my guess is that abortion will remain illegal in Northern Ireland for some time to come, but I am always prepared to be proven wrong.