Lawyers get everywhere these days, and nowhere more so than the Competition Commission's reporting panel. Four of the most recent intakes to the panel, appointed in 2005, were previously star City competition law practitioners – Laura Carstensen (Slaughter and May), Chris Bright (Shearman & Sterling), Richard Taylor (CMS Cameron McKenna) and Rob Murray (Clifford Chance) – while that year's intake also included another former CMS Cameron McKenna partner, Law Society president Fiona Woolf, whose specialist areas include regulatory and market design.

They joined longstanding legal panel members Laurence Elks (a competition lawyer who was formerly a partner at Nabarro Nathanson), former BAT assistant general counsel Martin Walzer and Dame Barbara Mills QC, former Director of Public Prosecutions and director of the Serious Fraud Office.

Additionally, the current chairman, former Simmons & Simmons partner Peter Freeman – who joined the commission in 2003 – is also a former City competition lawyer, as is one of the three deputy chairmen, Diana Guy, a former partner of Theodore Goddard who has been a member of the Competition Commission since 2001.

While the legal takeover of the commission's reporting is not quite as dramatic as it might seem – lawyers comprise around a fifth of the reporting panel's members, who also include academics, economists, accountants, civil servants and financiers – the recruitment of so many leading lights from the law is a relatively new development and an indication of the changing role and structure of the commission.

The Enterprise Act 2002 revolutionised the role of the Competition Commission. Formerly an investigative body that could only make recommendations to the secretary of state for Trade and Industry, the Commission now has the power to not only decide whether a merger should go ahead or a market should be reformed, but also put its recommendations directly into action. At the same time, the test applied to its investigations was changed from the rather nebulous criterion of whether a merger, market or regulatory regime was 'in the public interest' to more specific and economically-focused competition benchmark.

The Enterprise Act also created a new specialist appeal mechanism, the Competition Appeals Tribunal (CAT) to hear appeals against decisions made by the commission as well as those of the Office of Fair Trading (OFT) and regulators of some of the formerly nationalised industries such as telecoms, rail, gas and electricity.

The consequences for the way the Competition Commission operates have been significant, to say the least.

"They have very great powers now," says Martin Coleman, head of the competition department at Norton Rose. "The process has become more legalistic since the Enterprise Act and the scope for challenging the commission's decisions is much greater. They do not just report, they implement. Therefore they need to be more precise in the way they go about things, and lawyers' skills become more relevant."

Whether it is a direct consequence of the increased number of competition lawyers on the panel or not, practitioners with experience of presenting cases at the commission variously describe its approach and process now as more formal, forensic, focused and transparent.

"The vulnerability of the Competition Commission to having its decisions challenged has grown since the creation of the CAT," says George Peretz, a barrister specialising in competition law at Monckton Chambers.

"Disappointed parties will be more confident about appealing to a specialist tribunal that can get to grips with detail and issues than they would have been with the High Court. The Competition Commission has done an awful lot to tighten up its procedures – impressively so – to address its vulnerability to challenge."

But while Freeman dislikes the term 'legalistic' – "we are thorough, fair and open," he says – few private practice lawyers say this is a bad thing. "It was looser in the old days," Coleman says. "It is better now: people know where they are."

"In merger cases, the Competition Commission has been more forensic in its approach," observes Stephen Wisking, a partner in the EU/competition practice at Herbert Smith in London.

"They are more likely, for example, to refer to the party's original documentation to see if they support what they have been told verbally. There is also a greater preparedness to show their thinking and allow you to comment – it is less of a black box. That gives you a better opportunity to know what people are saying about your case and gives you the chance to respond."

One of the major reasons for the new approach is the increasing number of professionals appointed to the panel following the Enterprise Act. The Competition Commission's predecessor, the Monopolies and Mergers Commission (MMC), made a point of not appointing specialist panel members for fear that they were too close to issues to make clear recommendations in the public interest. The results, veteran competition lawyers say, were some fairly unpredictable decisions.

"The appointments of professional members has been extremely helpful," adds Andrew Finfer, a partner at Schofield Sweeney. "It has enabled them to direct their resources more effectively and led to the adoption of a more focused approach."

Within this professional band of members, specialist lawyers have a critical role – as well as the obvious advantages of their legal knowledge. Since the 'public interest' test was scrapped competition lawyers are also one of the few groups of professionals likely to have prior practical experience of a variety of cases before the commission.

Coleman says: "It is always helpful to have people on panels who understand competition law, but it is important they are not there as lawyers.

"They have to be careful not to just consider things based on points of law, but as long as they have experience of looking at competition issues in the round and in context, then their legal experience is a valuable asset. Their experience is more important than their legal skills – competition law is a narrow field and only advisers such as lawyers are likely to have direct experience of a number of different cases."

Indeed, the real value of the appointment of specialist lawyers to the commission's panel is less their legal knowledge, but their commercial nous. "All of these lawyers have been on the other side of the fence," Wisking says. "It is very valuable for the commission to have that insight into how companies deal with these issues. It helps to make their processes better."

But the revolving door approach to staffing regulatory bodies is not without its critics. The Competition Commission's sister body, the OFT, has been singled out by some as an example of an institution that has allowed its relationship with some of the companies it investigates to become too cosy. Could the same criticism apply to the Competition Commission?

There have yet to be any examples of panel members returning to private practice full-time, although as panel members are part-time, almost all have other commercial interests and activities.

However, the commission's sister competition bodies have both seen lawyers move back into private practice with Linklaters last year recruiting CAT president Sir Christopher Bellamy as a senior consultant and OFT director Simon Priddis moving to Freshfields Bruckhaus Deringer.

Freeman is unequivocal about the benefits of the 'revolving door' to his organisation. "It is a thoroughly good thing," he argues.

"We have appropriate statements on conflicts of interest, which are fairly robust. Our concern is that panel members do not take jobs with companies that have been investigated or use the information they have gained, but we have had no problems. I have no issue with panel members continuing to work in business as long as no specific information from their roles here is used, and I would have no problem in appointing a practising lawyer to the panel."

The view among competition practitioners is, in general, similarly sanguine. "The main focus should be clarity as to precisely what the position is if an individual has a dual role," says John Pheasant, competition partner in the London and Brussels offices of US firm Hogan & Hartson. "I am sure that the right checks and balances are taken at the Competition Commission."

The revolving door approach was pioneered in the US and Pheasant, formerly competition head at Lovells before joining Hogan last year, says that the experience of many of his US colleagues who have spent time at the Federal Trade Commission or the Department of Justice shows that there are benefits on both sides of the equation.

He says: "It provides the authorities with a better perspective and when the lawyers go back into private practice, they have a better understanding of the challenges that government agencies face and what their priorities are. It builds a better working relationship between advisers and competition authorities. The Americans handle the conflicts of interest very well – their rules are very clear. There is no reason why it should not work here."

Some practitioners suggest that the nature of the Competition Commission's work means that the public-private crossover is less of a perceived problem for its panel members than it might be at the OFT, for example. The knowledge they gain from the rather diverse collection of cases they work on is less likely to be useful to future clients than the inside track into longer-term policy and thinking they might gain at the OFT, for instance.

Perceived conflicts of interest are likely to become more of an issue, however, as working for bodies such as the Competition Commission is becoming more common midway through a career rather than at the end of it, and a number of the lawyers recently appointed to the commission are a long way off retirement.

But while there have been mutterings about conflicts, as far as the Competition Commission is concerned, the consequences of making the rules too strict, for instance by banning panel members from other activities while working for the commission, would be much worse.

"It is useful to have people who are still active in other areas because it keeps their experience up-to-date," Pheasant says. "It is the experience and the balance of the Competition Commission's panel that makes it a truly world-class class competition body."