Taoiseach Micheal Martin has refused to commit to the 100% redress scheme being sought by homeowners affected by the mica scandal.

It comes as thousands of protesters marched on the Dail in Dublin, with families and supporters travelling from Donegal and Mayo to take part.

Defective building blocks containing the mineral mica have caused cracks and fissures to open up in an estimated 5,000 to 6,000 homes primarily in the two counties.

Mr Martin said a six-week process will be needed to analyse the issues caused by the mica scandal and to “iron out” issues with the redress scheme.

He told the Dail: “Our view is we should set in train a time-bound process, lasting about six weeks, involving the Mica Action Group, representatives from the different counties, involving the local authorities, and also the department to work on the scheme.”

Mr Martin described the scandal as “appalling” and “devastating” for the homeowners.

However, he refused to commit to the 100% redress being sought by campaigners.

Sinn Fein leader Mary Lou McDonald welcomed the commitment to a time-bound process to address the issues with the redress scheme, first introduced in January 2020.

Sinn Fein is to table a motion in the Dail on Tuesday calling for 100% redress, and urged the Taoiseach to make a commitment to it.

She said: “The last scheme may have been introduced in good faith, Taoiseach, but the truth is that scheme has not worked.

“That scheme has left these families in misery, living this nightmare, day after day, night after night, and that must stop.

“We know that the only sustainable viable redress is 100% redress.”

The Taoiseach responded by saying “100% of what? It’s not as simple as asserted.”

He added: “There’s a whole range of issues we’ve got to discuss, in terms of the grant caps themselves, in terms of the allowable costs, engineering costs, upfront costs, and how we can make it easier for the homeowners.

“That’s what we want to do.”

He said Housing Minister Darragh O’Brien had consulted with the Mica Action Group and is anxious to get the process up and running “as quickly as possible”.

Mrs McDonald repeatedly asked the Taoiseach during his response if he would commit to 100% redress, which did not receive a response.

Addressing the Ceann Comhairle, she said: “I want to object to the Taoiseach studiously refusing to answer a very straightforward question.”

The Taoiseach noted that 33% of homes affected will have to be rebuilt and the cost of the scheme is likely to exceed one billion euro, and he said there is a responsibility on designers and builders involved in the building of the homes.

Mr Martin added: “Generally speaking, we want to do the right thing by those who were let down by the provision of these defective blocks, which have rendered homes in many instances unliveable and has created great anxiety, and we’re going to do that.”

Later, the Taoiseach told Donegal TD Thomas Pringle that he had an issue “with certain people walking away from this”.

He said: “The state can’t forever be held accountable alone, in respect of behaviours or actions where others fell short, be it in the private sector or elsewhere.

“I wanted the Attorney General to examine that, not just for this Government but for the future governments and more importantly for taxpayers.

“I’m very clear about our role in helping the homeowner, but I think there’s a separate piece of work needed as well, to examine this in greater detail.”