The overwhelming majority of cases - 413, amounting to 64 percent of the total - were targeted against the European Commission.

The report goes on to recount how the European Personnel Selection Office received 14 percent of all complaints, while the European Parliament received nine percent and the European Anti-Fraud Office three percent.

The council, representing EU governments, managed to worry one percent of complainants.

Some 28 percent of complaints fall into a 'lack of transparency' rubric, with Mr Diamandouros saying this fact should provide "an opportunity for EU institutions and bodies to demonstrate their willingness to be as open and accountable as possible".

"I hope that the commission's proposals for reform of the legislation on public access to documents will contribute to realising this important goal," he added when presenting the 2007 report on his activities.

To illustrate the difficulties people face in contact with EU bodies, the report mentions a Maltese journalist's request for access to details on the payments received by MEPs such as payments for general expenditure, travel and subsistence allowances, as well as allowances for their assistants.

The European Parliament turned down the request, arguing it would violate data protection - an argument rejected by the ombudsman, after consulting the European Data Protection Supervisor. The inquiry is still ongoing, however.

Absolute transparency diminishes privacy, while absolute privacy undermines transparency, the ombudsman said, calling on EU institutions to strike the right balance.

Ombudsman's statute

The report comes as Liberal lawmakers in the European Parliament (ALDE) are pushing for a review of the ombudsman's duties in order to allow him access to classified documents if needed.

But these efforts have been temporarily frozen due to objections from the parliament's two major groups, the conservatives (EPP-ED) and the Socialists (PSE) - something that the liberals read as a "reluctance to greater transparency".

"It is very regrettable and quite extraordinary that EPP and PSE show so little enthusiasm on matters of transparency," UK Liberal Democrat MEP Andrew Duff said.

"This delay is irresponsible, since the Slovenian [EU] presidency has explicitly asked us to deal with this matter rapidly," Mr Duff added.

Mr Diamandouros, for his part, said he was "still waiting for the decision by the parliament".

"I very much hope there will be a decision on a compromise, which I think is a fair one," he added.

The statute of the ombudsman is now to be discussed during the upcoming plenary session in Strasburg (21-24 April).