UK Liberal Democrat MEP Wallis, who is representing the Parliament in talks with Commission Vice-President Maroš Šefčovič, said Belgian Foreign Minister Steven Vanackere had asked the Council's Committee of Permanent Representatives to "review" plans to establish a single register for all three institutions at the close of the General Affairs Council on 13 September.
"If this materialises, it will represent a welcome evolution in the Council's position," said Wallis.
Talks on establishing a joint lobby register between the Commission and the Parliament resumed in May without the Council's involvement.
Indeed the Council, which represents governments, is yet to participate in the inter-institutional working group's work. Many of its employees are seconded from national posts at home, making their inclusion in an EU register more difficult.
"Until now, we have always met with a brick wall when we invited the Council to take part in the negotiations to set up and coordinate the lobby registers of the Commission and Parliament," said Wallis, who sits in the Alliance of Liberals and Democrats for Europe (ALDE) group in the EU assembly.
The joint register for the Commission and the Parliament, which is expected to be up and running by June 2011, will be voluntary at first.
"With the Council on board, however, we may have more hope of a chance of making this system mandatory in the long run," said Wallis.
Towards 'transparency register'?
Meanwhile, the European Commission's voluntary lobby register may be renamed "transparency register" when it is merged with the Parliament's system, a senior Commission source told EurActiv today.
"To avoid the moniker 'lobby register', it might be called 'transparency register'. Additional categories could encourage further circles such as think-tanks and regional bodies to register. These changes could be launched at a conference jointly organised by the Commission and the Parliament," the source said.
Commission register hits 3,000 mark
The EU executive's register, launched by Šefčovič's predecessor on transparency issues Siim Kallas in 2008, last week (6 September) surpassed the 3,000 entries mark.
"The steady increase in registrations shows that we are on the right way," said Šefčovič, describing the milestone as "an encouragement for the joint Commission-Parliament register we are working on".
The two institutions will hold a joint information seminar on the common register on 6 October. Both Wallis and Šefčovič are set to speak at the event.