“It’s mystifying as an institution ... By definition, there is nothing like it at the national level, and it stands apart from its peer institutions here in Brussels,” he said.

He said people could watch European Parliament debates or take part in public consultations on European Commission proposals, but he said “there’s nothing like that at Council level”.

He added that Council opacity is a pressing issue because power over EU policy has tilted from the Commission back to member states, making the Council, where thy meet, into an “agenda-setter”.

Dolan spoke on the occasion of a new TI study that showed how EU secrecy can harm the outside world.

Taking EU fishing quotas as an example, the study noted that “many fishing limits set annually by EU fisheries’ ministers regularly exceed scientifically advised levels”.

The study said this happened because when EU ministers negotiated behind closed doors their main concern was to go home with a good deal for their national fishing fleets.

That lack of accountability has led to overfishing of European stocks by 20 percent per year for the past 15 years, TI said.

Meanwhile, the Commission unveiled plans earlier this week for a mandatory lobbyist register to cover all the big EU institutions, including some Council diplomats.

The project comes amid broader efforts to regain public trust in the wake of Brexit and the migration crisis, but also amid lobbying controversies by top EU officials.

As things stand, the Council is the only EU body without any lobbyist register, but Dolan said it was “being dragged kicking and screaming into the light in terms of new social norms on transparency”.

Kicking and screaming

TI recalled on Thursday that a 2013 decision by the EU Court of Justice said the Council should publish details of each member state’s position on any given EU decision.

The EU’s ombudsman in July also published recommendations on making trilogues - informal negotiations between the Commission, the Council, and MEPs - more open to scrutiny.

Dolan told EUobserver there are signs that Council chief Donald Tusk is becoming aware of the problem.

"Everybody realises now the future is in their [member states’] hands, and it is not sufficient to blame the Commission or the Parliament, and I think this is becoming increasingly clear to the European public," he said

Alex Brenninkmeijer, a former Dutch ombudsman and a member of the European Court of Auditors, said on Thursday: “Transparency ... is part of taking people seriously in society”.

“It's the basis for trust in society,” he said.