Media playback is unsupported on your device Media caption The Democratic Unionist Party walked out of the chamber after attempts to derail the impending law changes failed

A last ditch attempt at the Stormont assembly to stop abortion law changes in Northern Ireland has failed, with the law set to change at midnight.

Unionist parties, who oppose the upcoming liberalisation, triggered the assembly's recall with a petition.

But politicians were told the assembly could not do any business until a speaker was elected with cross-community backing.

That became impossible when the nationalist SDLP left the chamber.

As a result no nationalist representatives remained, meaning no new speaker could be elected and the sitting was suspended after less than an hour.

Some unionist assembly members had been attempting to introduce the Defence of the Unborn Child Bill 2019, which they hoped to pass by midnight.

But the incumbent speaker, Robin Newton - who was elected as a Democratic Unionist Party (DUP) MLA - resisted attempts led by his party leader Arlene Foster to persuade him to suspend assembly rules to allow the bill to be introduced.

In July, MPs at Westminster passed legislation which requires the government to change abortion laws and extend same-sex marriage to Northern Ireland if devolution is not restored by 21 October.

Northern Ireland Secretary Julian Smith told MPs on Monday that the first same-sex marriages in Northern Ireland will be in the week of Valentine's Day 2020.

Monday's sitting was the first time the assembly had sat for nearly three years.

The DUP also walked out, saying this was not the end of the matter.

Mrs Foster said it was a "shameful day" which would leave Northern Ireland with Europe's most liberal abortion laws.

Sinn Féin, the Alliance Party, the Green Party and People Before Profit did not take part in the assembly session, which Alliance leader Naomi Long called a "cynical political stunt".

Analysis: Another bizarre day at Stormont

By Mark Devenport, BBC News NI Political Editor

Stormont has witnessed some pretty bizarre days before.

Rumbustious exchanges over the renewable heat scandal, a police raid on the Sinn Féin office, the sight of the armed loyalist Michael Stone jammed in the doors by the brave security staff who thwarted his attempt to kill Gerry Adams and Martin McGuinness.

October 21, 2019 did not quite match that last piece of - to quote Stone - "performance art". But it was fairly extraordinary.

Pro-choice campaigners stood on the wide slope heading towards Stormont with giant letters spelling out the word "decriminalised".

Anti-abortion activists gathered on the plinth at the bottom of Carson's statue, declaring changes to the law on abortion were not happening in their name.

Cheers rang out as the DUP's team marched into the assembly chamber.

However, within the hour the proceedings dribbled to an anti-climactic end.

Read more from Mark here.

Northern Ireland has been without a devolved government since January 2017 when the power-sharing parties - the DUP and Sinn Féin - split after a bitter row.

Without an executive in place, Stormont cannot affect the abortion laws.

It is unlikely an executive will be established as it needs support from both the unionist and nationalist communities.

Why were politicians recalled?

Several rounds of talks to restore the executive since its collapse have not succeeded.

MPs in the House of Commons have since passed some key legislation for Northern Ireland.

Image caption Sarah Ewart, who was denied an abortion in NI in 2013, was among those outside Stormont

Speaker Robin Newton said the assembly had to elect a speaker with cross-community support as its first business, and could not suspend assembly rules - known as standing orders - first to consider the Defence of the Unborn Child bill.

However, the DUP's Paul Givan said: "The legal opinion of the attorney general is crystal clear... that it is permissible to suspend standing orders to proceed with business."

The bid to recall the assembly was proposed by Northern Ireland peer Baroness O'Loan, who opposes any reform of the existing abortion law.

The petition was signed by 27 DUP assembly members, Ulster Unionist leader Robin Swann and his party colleagues Robbie Butler and Roy Beggs, as well as Traditional Unionist Voice (TUV) leader Jim Allister.

What are the current rules on abortion in NI?

Northern Ireland's abortion legislation is very different from the law in Great Britain.

The 1967 Abortion Act, which liberalised the rules in England, Scotland and Wales, was never extended to Northern Ireland.

Currently, a termination is only permitted in Northern Ireland if a woman's life is at risk or if there is a risk of permanent and serious damage to her mental or physical health.

Rape, incest or diagnoses of fatal fetal abnormality - where medics believe that a baby will die before, during or shortly after birth - are not grounds for a legal abortion in Northern Ireland.

Is there anything you'd like to know about this story or wider issues around it? Send us your questions. If you are reading this page on the BBC News app, you will need to visit the mobile version of the BBC website to submit your question on this topic.

What will happen at midnight?

Abortion will be decriminalised if the devolved government is not restored.

The legislation brought in by MPs at Westminster means the UK government will assume responsibility for introducing new regulations to provide greater access to terminations by next April.

Under the act, same sex marriage will become legal in Northern Ireland in January, with the first wedding expected the following month.

What positions are the NI parties taking?

Speaking on Monday afternoon, Sinn Féin leader Mary Lou McDonald welcomed the "decriminalisation of women that will take effect from midnight".

She said: "The circus and the farce today in the assembly chamber demonstrates very clearly that what we don't need is political games, we need serious politics."

The SDLP has described itself as a "pro-life party" but its politicians are free to vote with their conscience on abortion laws.

After leading his assembly members out of the chamber on Monday, party leader Colum Eastwood said: "The DUP are not serious about getting Stormont back to work.

"These institutions are in grave danger. There cannot be a unionist talking shop."

Image copyright Pacemaker Image caption Stormont returned briefly, but not to hold talks - the focus was on the issue of abortion

DUP MLA Gordon Lyons said his party wanted to return to Stormont to "take decisions on issues that matter to the people of Northern Ireland".

The Ulster Unionist Party's 10 assembly members attended the sitting and the party also proposed a second petition to recall the assembly on Tuesday, but it has since withdrawn its signatures from this petition.

The UUP's Doug Beattie said his party's petition was for assembly members to express anger about the collapse of devolution more than 1,000 days ago.

He denied the UUP was engaging in "stunt politics" of its own and said something needed to be done given the absence of formal talks to restore power-sharing at Stormont.

Image caption Both sides of the abortion debate held protests at Stormont

Alliance Party leader Naomi Long said none of her party's assembly members would be attending and she described the recall as a "cynical political stunt".

"The intention of this recall is not to block abortion law and equal marriage but to create the illusion the DUP are trying to do so," she added.

Green Party leader Clare Bailey said it was a "shameful pantomime" and that she would not enter the chamber.