Theresa May has faced calls to push for reform of Northern Ireland's abortion laws after the Irish referendum.
If the landslide indicated by exit poll data in Ireland is confirmed, Northern Ireland will soon become the only part of Britain and Ireland where terminations are all but outlawed.
Liberal Democrat leader Sir Vince Cable said the Prime Minister should take advantage of the current lack of a devolved administration and push for reform from Westminster.
Senior civil servants have been taking the majority of decisions within departments in Northern Ireland since the powersharing administration at Stormont collapsed 16 months ago.
Sir Vince told the Press Association: "I believe in the principle of the right to choose, I think in the rest of the UK we have a sensible balance.
"The position in Northern Ireland is now highly anomalous and I think, probably, action will now have to be taken."
Asked if Mrs May should intervene, he said: "As long as you have devolved elected bodies then one has to respect their preferences, whether it's Scotland, Wales, Northern Ireland or London.
"Since there is, effectively, direct rule from Westminster, the Government has responsibility and it can and should take the opportunity to deal with this issue properly."
Abortions are currently only legal in Northern Ireland if the life or mental health of the mother is at risk.
While political leaders south of the border were at the forefront of efforts to liberalise the law during the referendum campaign, a majority of politicians in Northern Ireland do not favour the radical law changes now proposed in their neighbouring jurisdiction.