MSPs have held "constructive" talks at the House of Lords on the urgent need for amendments to key Brexit legislation.
A delegation of senior Scottish parliamentarians raised concerns over the EU Withdrawal Bill directly with Minister for the Constitution Chloe Smith during the inter-parliamentary forum on Brexit.
Bruce Crawford, the convener of Holyrood's finance and constitution committee said that while the minister was in "listening mode" it was now "time for action".
Both the Scottish and Welsh Governments have branded the legislation a "power grab", saying they cannot recommend it be granted consent in its current form, which would see EU responsibilities in devolved areas initially transferred to Westminster.
Amendments to the problematic clause 11 were promised during the report stage in the Commons but are now expected to emerge in the Lords.
Representatives of three Holyrood committees attended the forum, which brings together the relevant committees from both Houses of Parliament and the devolved legislatures.
Speaking after the meeting, Mr Crawford said: "The Minister for the Constitution was there and she certainly involved herself constructively with us and listened to what was being said, but I think it's quite clear it's not just members of the Scottish Parliament who believe that clause 11 is incompatible with the devolution settlement.
"That concern was shared by the Brexit forum and indeed I think it's fair to say there was a view that there is now urgent action needed from the UK Government to bring forward the amendments and share them with the Scottish Government to make sure we avoid any potential constitutional conflict.
"It's quite clear also that if clause 11 is not either removed or replaced that there will be no majority in the Scottish Parliament to pass a legislative consent motion. In these circumstances that takes us into the constitutional crisis arena."
Mr Crawford added that Ms Smith "was in listening mode but I think we're really getting beyond the time for listening and it's time for action".
"The ball is now firmly in the court of the UK Government.
"It's my understanding that no words around the potential amendment have yet been shared with the Scottish Government, but a deal is possible.
"I think neither side, neither the UK Government nor the Scottish Government, wants this to end up in a constitutional conflict and want to find resolution but the ball is firmly in the court of the UK Government at this stage."
A UK Government spokeswoman said: "Every part of the United Kingdom needs a functioning statute book, and that applies as much to Scotland as elsewhere.
"We have made good progress in our discussions with the Scottish Government on common frameworks and we look forward to making significant further progress over the coming weeks.
"We have made clear that we will bring forward an amendment to clause 11 of the Bill in the Lords, and are confident we can get to a position which has the support of all sides."