Alena Gajduskova, a a member of the Czech Senate, reacting to Klaus' apparent reluctance to sign the EU's Lisbon reform treaty, suggested an impeachment motion is likely if he declines to sign the document approved by both chambers of Parliament, the Czech Web site tyden.cz said Monday.
Czech senators Wednesday approved the Lisbon treaty, which would reform the decision-making process in EU administration.
Klaus opposes the reform treaty, saying it would hurt Czech sovereignty.
Czech Foreign Minister Jan Kohout said Klaus should sign the treaty, but would not say whether Klaus is legally bound to do so, Prague Radio said.
Presidential assistant Ladislav Jakl said the Czech Republic's ratification would be legally accomplished only when signed by the head of state, Czech Television said Sunday.
Jakl, a member the president's office, said a group of senators could submit a petition to the Czech Constitutional Court asking for a review of the document.