William Hague will today launch an unprecedented attempt to chart all the powers that the European Union has over Britain.
Every Government department will be ordered to establish which areas of everyday life are affected by EU regulations. The plan is to compile a complete audit of how Europe impinges on individuals, businesses and government.
The Foreign Office stressed that the audit was not about trying to identify which powers the Government might try and repatriate or scrap.
However, many Conservative MPs hope the study will lay the groundwork for a future Tory-only government to renegotiate a new membership deal with the EU.
The Liberal Democrats fear the exercise could be seen in other European capitals and Washington as a sign that Britain wants to move further from the EU mainstream. They are said to have pressed for the audit to be low key.
Under the proposals, to be announced by the Foreign Secretary in the House of Commons today, each Government department will call for evidence on areas for which they have responsibility from "anyone with knowledge or expertise in any area of EU activity". The audit will start in the autumn and is expected to be completed by late 2014.
A Government source said: "The point of this is that there are many people out there who have a far better idea than Government of how Europe affects them in their everyday lives – both good things and bad things. For example businesses know which regulations stop them from growing but they also understand the advantages of the single market and how that could be expanded. We are not prejudging the nature of the contributions – this is purely about allowing us to have an informed debate."
Officials close to Mr Cameron insist the Prime Minister is not about to start a fight to reclaim powers from Brussels any time soon and will certainly not make it his price for supporting eurozone moves towards closer fiscal and political union. However, the audit could be used by the Conservatives as a basis for its next election manifesto.
Mr Hague is expected to say today that all EU countries have big choices to make and there is "deep disillusionment" with Brussels. He will argue that the audit will help to make the "debate in the UK and the decisions we will have to make as well-informed and fact-based as possible".