The Scottish Government has been warned that independence could see the country overrun with nuclear waste.
The MP for Sellafield, Jamie Reed, has written to the First Minister Alex Salmond to tell him that international rules mean there would be restrictions on how much radioactivity Scotland could export to England.
In his letter, the Labour MP explains:
In other words, under independence, Scotland could only export as much radioactivity as it imports, potentially restricting the amount it sends to Sellafield for storage.
That could then require a separate storage arrangement in Scotland.
In addition, Mr Reed says the most highly radioactive waste is not permitted to be transported from one country to another.
This means waste from Hunterston and Torness reactors could be prevented from being stored at Sellafield and would have to be dealt with in Scotland instead.
A statement is expected from the Scottish Government.