In the shadow of the EU Parliament in Brussels, under a grand white tent filling a museum garden, hundreds of lobbyists, officials and lawmakers hobnob as the cava flows.

The end-of-summer networking bonanza was organised by 20 business groups representing everything from cars to clean energy, digital to detergents.

The message? The European Union needs to "listen to industry" more, according to Alain D'haese of the European Aerosol Federation.

Dubbed "The Party -- Back2Business", the Wednesday event marked the return to work for lobbyists -- and came a week before a major policy speech by EU chief Ursula von der Leyen.

"There is no better moment to bring in business leaders to Brussels to reconnect with EU stakeholders and to reiterate our priorities," said Alexis van Maercke of Detergents Europe.

Home to the EU's key institutions, Brussels is the European capital of lobbying, with as many as 30,000 lobbyists working to represent specific interests and influence public policy in the market of 450 million people.

Evenings can be swallowed up by a smorgasbord of networking soirees across town, especially in September when eurocrats and lobbyists alike land back from summer break.

- Changing political winds -

Nearly 18,000 organisations including lobbying firms, consultancies, multinational corporations, trade unions and civil society groups are listed in the EU's Transparency Register.

The register allows them to advocate on behalf of their interests and is part of the EU's attempts to keep the process open and accountable.

Industries are riding the pro-business wave in Brussels.

The EU has over the past two years adopted a more business-friendly stance, as the bloc fears its firms will fall further behind China and the United States.

Brussels has rolled out a wave of measures to ease regulatory burdens, to the dismay of environmental groups whose concerns were until a few years ago seen as core to EU policymaking.

Lobbyists these days have "more work", said Umberto Gambini of consultancy Forward Global, which represents, among others, companies in the tech sector.

The tide has turned in industry's favour since von der Leyen's second mandate began in late 2024 because the EU realised some of its green rules benefitted non-European rivals, according to Paul Varakas of the European Cigar Manufacturers Association.

And alongside the sparkling wine, the money is flowing.

The largest companies -- including US-based Big Tech -- poured around 382 million euros ($442 million) into lobbying in the past year, a study by civil society groups said this summer.

That was up 7.8 percent from 2025's reporting.

- 'We're transparent' -

Lobbying remains dogged by a reputation as a shadowy trade.

"People have a negative image of lobbyists. They picture secret deals in dark corridors. The reality is very different," D'haese said.

"We're transparent," he added. "We explain how our sector works. There's a great deal of integrity in this profession. Otherwise, you don't last long."

"The burden of proof on transparency is not only for the private sector, but it's also imposed on institutions. You can see who they meet, the meetings. They need to record it, which is very good," Gambini said.

But the image problem persists.