The Stormont Assembly will be recalled later in a doomed bid to pass a new law on organ donation in Northern Ireland.

Rival parties are attempting to ramp up the pressure on the DUP to end its boycott of devolution, but the unionist party has made clear it will again block any attempt to elect a speaker.

The recall petition is attempting to get MLAs to implement a new opt-out organ donation law inspired by Belfast boy Daithi MacGabhann, six, who is waiting for a heart transplant.

A petition tabled last week by Sinn Fein’s Stormont leader Michelle O’Neill gained the requisite 30 MLA signatures to secure a recall of the crisis-hit institutions, which will take place at 12pm.

Several previous attempts to reconstitute the Assembly have already failed as the DUP has not supported the election of a speaker at the outset of the sittings.

Without a speaker in place, the Assembly cannot proceed with further business.

DUP leader Sir Jeffrey Donaldson confirmed his party will again block the election of a speaker on Tuesday.

The region’s largest unionist party has refused to engage with the devolved institutions in Belfast since last May’s Assembly election, meaning it has not been possible to form a ministerial executive.

The boycott is part of the DUP’s campaign of opposition to Brexit’s Northern Ireland Protocol and the party says it will not return to powersharing until decisive action is taken to remove the protocol’s economic barriers on trade between Great Britain and Northern Ireland.

Negotiations between the UK Government and the EU to resolve differences over the protocol are continuing.

The opt-out organ donation system was passed by MLAs last year, but the secondary legislation required to implement it cannot be approved in the Assembly due to the current political stalemate.

The opt-out system would mean adults in Northern Ireland would be presumed to be donors, unless they take a decision to opt out. It is being implemented to increase donation rates in the region.

If the Assembly cannot pass the secondary legislation, then attention will turn to Westminster where the DUP has introduced an amendment to the Government’s Executive Formation Bill to facilitate the passing of the regulations.

The Bill deals with the legislation required to extend a deadline for holding a fresh Assembly election in Northern Ireland.

It will be for the Speaker’s Office at Westminster to decide whether to permit the DUP’s planned amendment on the organ donation regulations.

The NIO has cast doubt on the prospect of it being permitted, saying the scope of the Bill is very narrow.

An NIO spokesman said: “The Department for Health has laid the statutory rule to enable the Assembly to progress the legislation, meaning that the election of a speaker would allow this important and life-saving piece of legislation to be addressed this week.

“The Executive Formation Bill is focused solely on the Executive formation period and the secretary of state’s corresponding election duty and, as such, it consists of only one substantive clause only.

“The scope of the Bill is therefore very narrow, and amendments on issues other than the Executive formation period are highly unlikely to be in scope.

“The secretary of state urges the NI parties to come together on this and reminds them that people in Northern Ireland expect and deserve the devolved institutions to be functioning fully.”

Daithi underwent another heart procedure in England last week.

His father, Mairtin MacGabhann, has called on Northern Ireland’s politicians to do all they can to get the law implemented.