Religious leaders say the Government's plan to focus solely on state child sex abuse would've been unfair.

After months of campaigning, religious institutions are now included in the scope of the inquiry in to historical abuse.

Bishop of Dunedin Father Michael Dooley told Mike Hosking he understands the government's resistance to widen the scope.

"But the problem was that once they were to started that, then there'd be many people coming forward that wouldn't have been covered by it, so it would have become increasingly unfair."

The inquiry is due to report back by the end of 2020.

LISTEN TO MICHAEL DOOLEY TALK WITH MIKE HOSKING ABOVE