Plans to light up Belfast City Hall to mark Safe Abortion Day will not go ahead on Monday after the Democratic Unionist Party (DUP) used a council procedure to challenge the decision.

The landmark was due to be lit up green, after a request by the National Women's Council of Ireland and a motion brought to the council by the Alliance Party.

That motion was opposed by unionist parties and anti-abortion organisations.

Belfast City Council said they are now seeking legal opinion on "the merits" of the call-in procedure used by the DUP, but BBC News NI understands because the process will not be completed by Monday, the lighting of the hall will be delayed.

A "call-in" can be requested by 15% of councillors, if they believe a decision was not properly considered - known as procedural grounds - or that it would disproportionately affect a section of the district, also known as community impact grounds.

The council can then ask a lawyer to examine the decision.

Belfast City Council said the call-in by the DUP was received "both procedural grounds and disproportionate community impact grounds".

The DUP councillors then brought forward a proposal to stop the illumination, which was defeated.

An open letter, signed by a number of Christian and anti-abortion groups including Precious Life, was also sent to the council, calling on them to reject the plans to light up Belfast City Hall.

A private citizen, who wishes to remain anonymous, also lodged a lawsuit against the action.