More clarity is being sought from the Scottish Government on proposals to use the east pier at Stranraer as an overspill lorry park in the event of a no-deal Brexit.
The emergency plans featured in a statement made at Holyrood this week by Deputy First Minister John Swinney.
Dumfries and Galloway Council, Transport Scotland and other agencies have been looking at overflow contingency measures for Cairnryan ferry ports should there be a surge in traffic or other delays.
Alister Jack, as MP for Dumfries and Galloway, is seeking more information from Mr Swinney, who outlined a no-deal scenario where traffic flows between Northern Ireland and Scotland increased.
If extra demand does create a need for additional stacking capacity, estimates suggest the Stena's former ferry pier at near-by Stranraer could hold up to 300 HGVs.
The UK Government has so far given, or allocated, almost £140 million funding to the Scottish Government to make Brexit preparations north of the border.
Mr Jack, who stressed his strong preference to leave the EU with a deal, asks the Scottish Government for details of any discussions between their officials, the local authority and Police Scotland.
In a letter to Mr Swinney, the MP asks: "Has an impact assessment been carried out on the effect of this proposal on the town of Stranraer and the local area?
"What, if any, consultations have taken place around this proposal and whether there are any further plans to consult the local community?
"As you will also be aware, the poor condition of the roads around the Port of Cairnryan, namely the A75 and A77, remains a real concern for local residents, businesses, ferry operators and hauliers."
Mr Jack stated that any additional heavy traffic on the roads would create further pressures and he urged the Scottish Government and Transport Scotland to outline any steps being taken to deal with such issues.