The four main party leaders in Northern Ireland have written to Westminster MPs to state their opposition to plans to extend the 1967 Abortion Act.
It has been reported that an amendment could be tabled to the Embryology Bill which would extend the Abortion Act to Northern Ireland.
The Human Fertilisation and Embryology Bill is due for a second reading in the House of Commons on Monday.
Jeffrey Donaldson, chairman of the assembly's pro-life group, said: "The pro-life group in the assembly thought it would be useful for the four leaders to write to each MP re-stating that position.
"I think it's a very powerful message we have here, four political leaders coming from very diverse political perspectives but united in their view that we do not want the 1967 Act, with all its implications, imposed on Northern Ireland.
"The issue of abortion is a matter that should be left to the assembly itself."