A full inquiry into all of sales made by Nama could take up to 20 years to complete, the Taoiseach has warned.
Enda Kenny has said that he wants a forthcoming Commission of Investigation to focus solely on the sale of Nama's Northern Ireland loans.
Opposition TDs want the inquiry widened to look at other activities, with some calling for Nama sales to be suspended entirely.
However, Enda Kenny is opposing both ideas, saying that Nama must be allowed to continue its work, including building new homes.
"Obviously, when you consider their involvement in the special development zones, the delivery of 20,000 houses as part of the housing programme, the fact that they, in accordance with their own act, that they would expect to be concluded two years ahead of schedule, speaks for itself," he said.