British MPs to debate EU 'referendum lock'

If passed by the British parliament, the new bill would ensure that any "significant" EU treaty changes must be approved by a national referendum in the future.

Ministers would be able to wave through treaty changes deemed as "not significant", something London is expected to do regarding the establishment of a permanent European Stability Mechanism to aid struggling eurozone states.

Any example of government rather than citizen approval would be open to challenge via a judicial review however.

Proposals to introduce the 'referendum lock' on European powers were first suggested by David Cameron in 2009 after he ruled out a referendum on the Lisbon Treaty following its ratification by all 27 EU member states.

UK foreign secretary William Hague defended the plans over the weekend as "the strongest defence of national democracy put in place anywhere in Europe", but eurosceptic Tories are unconvinced.

Individuals such as veteran backbencher Bill Cash, Conservative chairman of the British parliament's European scrutiny committee, say the new law will fail to increase the democratic say.

"It was sold as a bill that was going to increase the power to the people," Mr Cash told the BBC. "In fact, what it does is undermine the power of the people by giving greater opportunities and gateways for the judiciary to be able to assert its ultimate authority over parliament and that is not a good thing."

The opposition Labour Party has described the bill as a "dog's dinner", arguing that the government should focus on restoring economic growth and jobs, rather than incessantly striving to appease Conservative eurosceptic MPs.

While Mr Cameron has so far avoided even a modicum of the trouble that has plagued former British leaders, the Conservative prime minister has been careful not to appear soft over the 'EU question', with his electorate traditionally more cautious on the subject than in many member states on the European continent.

In a series of battles with the European Parliament late last year, Mr Cameron led the member state charge against a six-percent increase in the EU's 2011 budget, although the final figure of 2.9 percent was far above his initial call for a spending freeze.

More budgetary battles are expected this year as EU institutions and member states prepare to negotiate the EU's long-term spending programme, post 2013.