Conservative MP Mark Harper is introducing a new Bill in Parliament today which will require Ministers to declare, on the front of every Bill and regulation, whether it is the result of a European Union decision.
The EU (Transparency) Bill intends to make the legislative process and the role of the EU in it more transparent and accountable to the public.
The Bill should be supported by anyone in favour of more honesty at Westminster. At the moment, nobody knows exactly what proportion of UK law derives from the EU - which has led to rows in the past.
Denis MacShane, for instance, claims the proportion is only 9%, compared with an estimate from the German Justice Ministry, which put the level at 84%.
Requring ministers to be honest about the root of each new piece of legislation is the only way to begin to put an end to that row.