Alliance MLA Stewart Dickson has said Brexit legislation is rewriting devolution without the input of MLAs.
The East Antrim MLA was speaking as MPs began debating the Committee stage of the EU Withdrawal Bill in the House of Commons. He said the current political impasse meant we had no input.
"This legislation has the potential to change the nature of the Good Friday Agreement in terms of the transfer of competencies from the EU to the UK, and to alter the balance of allocation of powers between the Assembly and Westminster.
"This should be a matter of extreme concern to any functioning Assembly, and the provisions of this Bill and any related legislative consent motion would be a matter of deep scrutiny by MLAs.
"By contrast, our counterparts in Scotland and Wales are deeply engaged around this legislation. Given the different nature of devolved powers and the different context here in Northern Ireland, we cannot rely upon them to defend our interests by proxy.
"This situation further reinforces the urgency for the full restoration of the Executive and Assembly."