The Mica Action Group has said it's "very disappointed" with a draft Cabinet memo that seeks to end the controversy over defective building blocks which have damaged thousands of homes.

Spokesperson Michael Doherty said a provision which states that principal homes would be included in the scheme, but not holiday homes and only some rental properties, appeared to be "bad faith, and would not go down very well."

He added: "There's no way we're going to let anyone be left out."

Details of the draft memo, published in the Sunday Independent, state that residents would be offered a full 100% grant for all remediation works capped at €420,000 - a significant increase on the previous scheme.

Mica campaigners say they'll also be watching closely to see what the final memo states regarding the cost per square foot of rebuilding an existing home. They say it needs to be €150 per sq ft.

Mr Doherty said the government "... cannot sell us short, as otherwise people could be out tens of thousands of euro."

The final memo could include a possible levy that would see the construction industry potentially paying into a fund towards the cost - estimated anywhere between €2 to €3 billion.

It's understood that the Cabinet memo is still be worked-on, and is described as "extremely complex", so it may not be brought to Cabinet by Housing Minister Darragh O'Brien this Tuesday.

Speaking on RTÉ's This Week Programme Transport Minister Eamon Ryan said that while he wasn't certain on the precise time - the issue would be considered by "within a week."