Lobbying used to be considered something strange and nasty that Americans do, something too vulgar for the rarefied legal circles of Brussels. It is still an activity that some lawyers, in particular continental European ones, frown upon. But, with the arrival of a number of US firms such as Winthrop Stimson Putnam & Roberts and Hogan & Hartson, which were keen to transplant client advocacy practices fine-tuned in Washington DC to the European market, it has since become an entrenched part of practice for many US and UK firms – although whether the lawyers call it lobbying is another matter.

Keith Hendry, resident partner at Clifford Chance's Brussels office, recalls being approached by a variety of specialist lobbying firms which were hoping to sell him their services: “We got them in and started talking to them. We then realised that we do that anyway.”

Take, for example, an anti-dumping case. As a matter of course, law firms will be required to speak to member states, send them submissions, and generally try to ensure that they are kept informed on what the situation is.

A similar process of speaking to the European Commission in an attempt to put forward a client's case applies to competition matters. As the vast majority of cases heard by DG IV, the competition directorate, are hidden from public view, there is plenty of scope for behind-the-scenes lobbying.

And increasingly there are other avenues for presenting a case. Numerous advisory committees help formulate EU policy on certain issues and, although their proceedings are secretive, if a firm knows who sits on them, it has a good opportunity to lobby.

The European Parliament meanwhile has become a key player in the EU legislative process thanks to the Maastricht Treaty, which gives it the ability to insist on amendments to directives. Euro MPs are now lobbied as a matter of course.

The game is about influence and lawyers see themselves as well-placed to take on the role. “We have the contacts,” says Hendry. And firms have been keen to establish a two-way street with the Commission to maintain those contacts. Lawyers are sent on secondment to the Commission, giving valuable insight into its operations as well as a knowledge of the people who pull the strings.

Meanwhile, former Commission officials are highly prized catches. Colin Overbury, former head of the merger task force, joined Allen & Overy as a consultant. John Ferry left his job as director of the competition directorate to join US firm LeBoeuf Lamb Greene & Macrae. Jacques Bourgeois, a principal legal adviser to the Commission, was taken on by Baker & McKenzie.

But there is a downside. On particularly high profile matters, officials have to contend with numerous calls every day from the lobbying pack in Brussels, which according to one estimate is 16,000-strong.

This is a cause of irritation at times – and attempts have been made to rein in the growth of the lobbying industry by the introduction of a code of conduct and a register of lobbyists.

However, Hendry believes that, although some officials are more open than others, on the whole the Commission welcomes constructive input from the lobbyist: “If they know you and they know you are acting on a particular case, the doors are open.”

Howard Liebman, a partner at US firm Morgan Lewis Bockius, agrees. “When it is done in a proper way, Commission officials usually don't mind it.” His firm, for example, has lobbied in a limited way on certain issues in the tax field.

Part of the problem for the Commission is that many directorates are understaffed. DG IV has a few hundred officials while the equivalent agency in the US has more than 2,000.

Input from lobbyists represents an effective way of gathering information so that sensible policy can be formulated.

But lawyers stress that arguments must be presented in a coherent fashion, not least because the officials that count are extremely busy. Anything that smacks too much of acting in the interests of a single client is frowned upon. Bribes are also not recommended.