By Tony Connelly, Europe Editor, Brussels

By any measure the current brand of Tory euroscepticism is more visceral, and poses more of a systemic threat to Britain’s EU membership than at any other time in the past 50 years.

Antagonism towards Europe has been building and now it’s coming to a head.

By pulling the Tories out of the centre-right European political group, the European People’s Party (EPP), David Cameron signalled he was prepared to submit to that force before he came to office.

By vetoing the fiscal compact last December – thus forcing 25 countries to seek an intergovernmental arrangement outside the immediate framework of EU law – Cameron showed he would also do it when in office.

When he recalled his defiance at the December summit at this week’s Conservative Party Conference in Birmingham he brought the house down.

Cameron wants Britain to stay in the EU but argues that the current journey by the eurozone towards deeper integration means it is time for Britain to seek a “new settlement” with the EU.

At the very least this will mean repatriating powers.

Foreign Secretary William Hague has launched a review of the competences the EU currently enjoys; it will become the mechanism through which Britain will attempt to claw back those powers it sees as encroaching on sovereignty or imposing too much red tape.

Others in his party want to go further and propose a much looser form of membership, one which focuses more on “free trade.”  Still more want a straightforward referendum on membership.

Euroscepticism has grown under Cameron’s watch, partly as a reaction to the UK Independence Party which is incessantly snapping at its flank.  The eurozone crisis, and the sense that Europe is holding the UK back in its quest for growth driven by trade with emerging economies, has hardened it even further.

Accordingly the number of Tory MPs who can now be called hard eurosceptics has risen dramatically.

Based on voting figures during the motion put forward by rebel MPs in October 2011 calling for a referendum on EU membership, Professor Tim Bale, author of The Conservative Party from Thatcher to Cameron, estimates that as many as 100 Tory MPs – or nearly one third of the party – are of the hard or medium-hard eurosceptic camp.

In a historical context that’s a lot. Margaret Thatcher faced only 10 MPs in the rebellion against the Single European Act, while John Major faced 41 dissident MPs over the Maastricht Treaty.

Professor Bale concludes that raw euroscepticism doesn’t just satisfy urges within the party, it wins votes as well, as poll results showed after Cameron’s return from Brussels last December.

“This is exactly what many eurosceptic conservatives had always argued: the harder the line the government took, the more the Party would get credit for it from the public,” he writes in a paper for the University of Warsaw’s British Socio-Political Studies Group.

Cameron’s promise to hold a referendum which falls short of a straightforward in-out question will infuriate dozens of Tory eurosceptics.

On their side is the British press, both tabloid and broadsheet, which has for years been softening up the public for a possible exit.  The scale of eurosceptic sentiment is at times breathtaking, and the European institutions appear to have thrown up their hands in countering the myths and misinformation.

According to a study by researcher Benjamin Hawkins (Nation, Separation and Threat: An Analysis of British Media Discourses on the European Union Treaty Reform Process the coverage of the EU within the British media follows two basic ideas.

The first is that the EU is a foreign power hostile to British interests (even though Britain is a member of the EU with its own commissioner, its own MEPs and with British ministers approving or rejecting legislation during council meetings in Brussels and Luxembourg).

The second is that the EU is a bargaining forum through which Britain’s interests are more or less outflanked by a powerful group of others, usually led by France and Germany.

Hawkins concludes that there is a “remarkable degree of consistency in the themes and assumptions evident in tabloids and broadsheets and dissenting voices [are] almost completely excluded from both.”

But with the conviction that the British public and media are behind them, Tory eurosceptics are looking for scalps, and have one particular chunk of EU policy in their sights.

‘Block opt-out’

Under the Lisbon Treaty, which Ireland ratified after a second referendum, many of the rules governing how EU member states co-operate in the field of policing, cross-border crime and criminal law were tightened up and became subject to the oversight of the European Court of Justice (ECJ).

The change means that the Luxembourg court can force member states to apply the rules they have signed up to.  It also removes the veto in the area of criminal justice.

Because of the difference between the British and Irish legal systems which are governed by “common law,” as opposed to the continental blend of Roman law and the Napoleonic Code, Britain was granted what’s called a “block opt-out” of Lisbon’s new arrangement.

The opt-out has a deadline.  The ECJ’s greater involvement doesn’t come into effect until 2014.  So if Britain wants to opt out of the 130 areas in the realm of cross border policing it has to do so before then.

The Tory manifesto at the last election already promised “to limit the European Court of Justice’s jurisdiction over criminal law to its pre-Lisbon level…”

Already 102 Conservative MPs have written a letter calling for the block opt-out to be exercised, so if Cameron agrees to a free vote in Westminster he would seemingly be throwing red meat to eurosceptic MPs and simultaneously winning popular support.

But observers will see this a cynical manoeuvre.  Britain can opt back in to perhaps scores of individual rules.

Furthermore, there are many in the British policing and security establishment who are concerned about a mass opt-out of EU cross-border policing rules.

Britain has traditionally been a key supporter of things like the European Arrest Warrant.  Indeed, it was instrumental in an operation to repatriate scores of British criminals living in Spain.

As a country with a huge international population and a major centre of trade the UK has also been a supporter of Europol, Europe’s law enforcement agency which brings together EU police forces to tackle cross border crimes such as trafficking, terrorism and drugs smuggling.

Hugo Brady, a senior research fellow at the UK-based Centre for European Reform (CER) has conducted a major study of the block opt-out.  He argues that while exercising the block opt-out en masse will boost Cameron’s eurosceptic credentials, it could leave Britain badly exposed in terms of security, while further alienating key allies.

“His claims to British legal exceptionalism are unlikely to convince other EU countries that the block opt-out is anything other than a shallow political manoeuvre,” says Brady.

‘People are losing patience’

That sense of Britain losing friends and influence has already been crystallising since Cameron vetoed the Fiscal Pact last December.  “There’s a real sense that people are losing patience with Britain,” says one seasoned Brussels observer.

It’s not just antagonising France and Germany, the countries with whom Britain has traditionally had a difficult relationship.  Britain was a key supporter of enlargement to the east, but even the new member states Europe are disillusioned at their ally’s increasing hostile posture.  Such countries are now devoting more attention to Germany, which has more investments in their territories, and more economic and political influence than the UK.

Britain’s attempts to cajole Poland into rejecting the Fiscal Compact back in December were, for many, the last straw.  Indeed, in a widely reported speech in Oxford last month the Polish Foreign Minister Radek Sikorski delivered a withering, if plaintive, assault on the rise of British euroscepticism.

“The EU is an English-speaking power,” he declared. “The Single Market was a British idea. A British commissioner runs our diplomatic service. You could, if only you wished, lead Europe’s defence policy.

“But if you refuse, please don’t expect us to help you wreck or paralyze the EU. Do not underestimate our determination not to return to the politics of the 20th century. You were not occupied. Most of us on the continent were. We will do almost anything to prevent that from happening again,” he said.

London is right to be anxious about the direction and deeper integration of the eurozone.  Such moves could distort the single market and put the UK at a competitive disadvantage.

But observers on this side of the Channel are warning that Cameron should tread carefully, and not submit to reflexes which might cost the country dearly in terms of influence and power.