Policy deliberation is considered an integral part of good policy‐making. In many policy sectors, however, the processes of participation are not developed enough to support the potential for policy deliberation. Expert deliberation carried out as a part of a wider policy process creates a challenging situation because participants are simultaneously expected to solve policy problems collectively while coping with the diverse interests of various stakeholder groups. In this article, I evaluate expert participation in three sequences of a waste policy reformulation process. Two of the sequences represent formal expert participation and the third a more informal one. Of particular interest in the evaluation is the participants’ ability to produce novel solutions for politically sensitive policy problems. The analytical framework for the evaluation is built on the trading zone metaphor inspired by Peter Galison's work. The results of the study indicate that the formal sequences of expert participation were characterized by the strategic behaviour of the participants, which made knowledge networking and the generation of novel ideas difficult, whereas the more informal sequence that was organized around one issue at a time was more capable of producing solutions to long‐standing policy problems. Additionally, the sequences with more formal participation did not contain the elements of interactional expertise associated with successful knowledge networking. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment