From aggrieved bank customers in the Netherlands to Spanish consumers angered by electricity blackouts, the idea of group damages claims is slowly taking root in Europe.

The latest example came only last week when disgruntled former shareholders in Northern Rock announced they were banding together to challenge the British government over the way the bank was nationalised.

Already, speculation over how far and how fast this trend might develop – and whether anything resembling US class actions could spring up on European shores – has alarmed business.

Consumer groups, on the other hand, try to play down the more exaggerated fears and argue that more needs to be done so that victims of corporate transgressions can get the legal redress they deserve.

Small wonder, then, that the European Commission has found itself deluged after entering this already simmering debate to ask for views on principles that could guide the development of a pan-European “collective action” system.

Before the Easter break, more than 80 submissions had rolled in, and more were promised. The closing deadline has been extended, for a second time, to March 31.

What the Brussels policymakers are ultimately trying to decide is whether an EU-wide system that allows consumers to bring group claims is necessary or desirable. Sounding out views on some common principles is a first step – to be followed by public workshops, an external study, and then some sort of statement by the end of this year.

In principle, the idea of group litigation makes sense: it is more efficient for numerous individuals who have similar, possibly modest, claims to be grouped together rather than pursue their cases separately. And already, according to European consumer organisation Beuc, 14 of the 27 EU countries have implemented their own domestic “collective redress” arrangements.

The concept of EU-wide collective redress also chimes well with Brussels’ desire to demonstrate that EU policies are meaningful at “grassroots” consumer level. Separately, the Commission’s powerful antitrust arm is looking at how private actions might be encouraged in the competition area, and is due to issue a White Paper, which will make firm proposals, next month.

But the gulf between consumer groups and business remains wide, and trying to hammer out consistency from myriad responses on key principles may prove to be difficult.

One major sticking point is how easy it should be for those bringing collective actions to get to court. For example, a Commission suggestion that defendants should not “artificially and unreasonably increase their legal costs” so that claimants are deterred from bringing actions because they may have to pick up their opponent’s legal bill if the action fails, has been welcomed by consumer groups but has concerned many corporate advisers.

Lawyers at Lovells law firm, for instance, say this “appears to be aimed at restricting costs that a defendant is entitled to incur when defending claims brought against it – this would impose a restriction on a defendant’s ability to properly defend a claim”.

Equally contentious is the suggestion that damages should be more than just compensatory. “A preventative effect for future wrongful conduct by traders or service providers is desirable – for instance by skimming off the profit gained from the incriminated conduct” is one of the Commission’s proposals.

But that worries business groups, which see it opening a back-door route to punitive damages. Beuc, on the other hand, recommends that the “skimming-off” process be complementary but separate, with the profits going into a “consumer protection fund”.

Lurking in the background is the much bigger debate about whether group litigation should work on an “opt-in” basis (where claimants must proactively choose to join the claim) or “opt-out” (where they are included unless they exempt themselves).

Many lawyers believe that the opt-out principle is one of the most serious flaws in the US class action system. There is also understood to be trenchant opposition to going down this route within the Commission, not least in its competition directorate.

But consumer groups, who generally favour the opt-out approach, have also begun to talk about hybrid schemes – where those consumers who made the effort to join an action might get individual redress, but damages could also be claimed generally on behalf of the remaining victims and donated to an appropriate charitable cause or consumer fund.

Deborah Prince, head of legal affairs at Which?, the UK consumer group, says: “We can conceive that opt-out may not be appropriate across the board – but I don’t think that means that you say we’re not going to have it at all”.

Those difficulties notwithstanding, the EU’s evolving patchwork of national collective redress systems is untidy and, lawyers warn, could lead to forum-shopping. “You already see plaintiffs going to one country rather than another,” says Emmanuel Gybels, at law firm Crowell & Moring in Brussels.

But harmonising litigation frameworks, even in a relatively new area, is a daunting task. “There is a massive argument for seeking to unify the procedures, but that would also be a massive endeavour,” says Diana Good, partner at Linklaters.

And she, like others, questions whether, at the end of day, the grassroots interest in pursuing many collective actions really warrants the effort. “Ultimately, people aren’t interested in pursuing claims for two euros or even £20,” she argues.