Assembly members are set to return to the Stormont chamber for the first time in nearly three years after 31 members signed a petition triggering a recall.
The move was proposed in a last-ditch attempt to stop the reform of Northern Ireland’s abortion law.
Laws on abortion and same-sex marriage in NI will change unless devolution is restored by Monday, 21 October.
So the recall will not affect the impending law changes, as it would need an executive to be appointed too.
On Thursday, the assembly Speaker Robin Newton wrote to all 90 MLAs informing them that the petition had reached the necessary 30 signatures, meaning the special sitting will take place on Monday.
The move had been proposed by Northern Ireland peer Baroness O’Loan, who opposes any reform of the current abortion law.
It was supported by campaign group Both Lives Matter, who collected the signatures from 27 DUP MLAs, Ulster Unionist leader Robin Swann and his party colleagues Robbie Butler and Roy Beggs, as well as TUV leader Jim Allister.
Confirming the target had been reached, DUP leader Arlene Foster said it will provide an opportunity for MLAs to show their opposition to the proposed law changes.
“Hopefully we will be able to debate the issue on Monday,” she added.
It is not clear if MLAs will be able to debate the abortion law changes as, first, they have to elect a speaker with cross-community support.
Sinn Féin will not be present and the SDLP is still considering its options.
Alliance said Monday’s sitting was “all about the denial of rights” and suggested it would not attend the session, but would instead “use appropriate opportunities to make our point”.
The Speaker said it was likely that the assembly would sit at 12:00 GMT on Monday, but that he would meet with party whips on Friday to confirm details.
The legislation that allows Stormont to be recalled in special circumstances is rarely used.
1,000 days without devolution
Stormont’s power-sharing government collapsed two-and-a-half years ago amid a bitter row about a green energy scheme and Parliament has had to pass some key legislation for Northern Ireland in the interim.
The DUP has publicly opposed Westminster legislating over the head of local ministers on abortion reform.
However, on Tuesday some questioned the timing of the party’s move over the recall petition.
In a tweet, Sinn Féin vice-president Michelle O’Neill described it as “a pointless political stunt”.
Ulster Unionist MLA Doug Beattie also dismissed it as a “stunt” and argued that it looked like a move by the DUP to claim to voters they had tried to do something in order to placate anti-abortion views.
Other Stormont sources believe the strategy is a “mega deflection” – an attempt to move the focus on the party from Brexit to something else.
The DUP said it has consistently called for the return of Stormont.
Independent unionist MLA Claire Sugden told BBC News NI she did not sign the petition, despite speculation she was considering it.
She said it specifically related to the abortion matter, rather than the wider issue of devolution not being in place for more than 1,000 days.