PRAGUE (Reuters) - The lower house of the Czech Republic`s parliament on Wednesday gave its final approval to the country becoming one of the first former Soviet Bloc members of the North Atlantic Treaty Organisation (NATO). The Chamber of Deputies voted in favour of joining NATO by a vote of 154-38 in the 200-seat lower house, according to a preliminary count. The Czech Republic, Poland and Hungary have been invited to join NATO in 1999. All NATO countries and the applicants` own parliaments must first ratify the expansion. The Czech upper house, the Senate, must still ratify the country`s membership, but the chamber is controlled by parties firmly in favour of joining the defence alliance. The measure in the lower house was opposed only by the Communist Party and the ultra-right Republican Party. Debate began on Tuesday just as it was announced that President Václav Havel, who has made NATO membership a top priority, fell critically ill with a perforated large intestine while on holiday in Austria. He underwent an emergency operation, and his condition has since stabilised. A recent poll by the private Czech demographics agency STEM showed that, if a referendum was held on the issue, 63 percent of potential voters would be in favour of NATO membership.