"I am convinced that a voluntary approach is much better than a mandatory one, because it offers an incentive to join," the commissioner told a European Policy Centre briefing on Friday.
Indeed, "many people who support a mandatory approach do not want any kind of register at all," he warned.
As of 17 April, 1,317 bodies had signed up. Describing this as "quite a number," the former Estonian prime minister said he would have considered 1,000 by June as a success.
Asked what changes should be expected when the Commission reviews the success of the register's first year in June, Kallas said: "I will never go to mandatory. That's my answer."
Speaking to EurActiv after the event, a Commission spokesperson later clarified that Mr Kallas had been expressing his satisfaction with the register's progress so far, and said the EU executive had not ruled out moving to a mandatory format at a later date if necessary.
Financial disclosure 'fine-tuning'
Instead, he identified financial disclosure of lobbying expenses as the main aspect to require fine-tuning. "Without financial disclosure, the whole exercise would have been irrelevant. But ten minutes before [the Commission's] final meeting to decide on the register, the issue was still open," Kallas said.
Debate has centred on the level of detail required, with transparency NGOs claiming that a requirement for law firms and consultancies to disclose revenue related to lobbying in brackets of €50,000 or percentage brackets of 10% is too broad.
But the commissioner warned against focusing too heavily on the issue. "Don't forget the commitments to good conduct you make by signing up too," he said.
Towards a common register?
Last May, a European Parliament report called for the creation of a mandatory register common to all three EU institutions (EurActiv 09/05/08). Kallas said ongoing negotiations between the Commission and the EU assembly in this regard were "very good", adding that another such meeting would take place this week.
"The idea is that registrants should not have to make different applications," he said. "The Parliament wants a common register before the elections, and it is realistic to expect that."
Security concerns
Nevertheless, "the kind of people who come to the Parliament is different from those who come to the Commission, so a common badge is not easy," Kallas cautioned, before warning that security would be an issue in any joint scheme.
"I am responsible for anything that might go wrong, and a badge allowing free access to the entire Commission premises would be unacceptable. It is more important to accurately know who is in the building," the commissioner further elaborated.
Asked whether he expected the Council to participate, Kallas said that institution had "not declared any interest in joining the register," but said the Parliament was putting it under pressure to change its governance system. "I don't know any more than that," he added.
The EU executive will review the success of its lobby register this summer.
