Poland's president on Thursday swore in a new judge to the Constitutional Tribunal as political conflict over appointments to the court seeped down to local authority level.

The conservative ruling Law and Justice party and the liberal opposition are locked in a conflict since December over new regulations on appointing judges to the tribunal. The new regulations have led to too many appointments being made, have paralyzed the court and have led some top judges and regional authorities to defy the government.

The conflict expanded to new levels this week, after three former presidents, including democracy champion Lech Walesa, appealed to ordinary Poles and politicians to observe the rulings of the tribunal rather than the legislation pushed by the government.

Their appeal met with immediate response from some city councils and local governments. Votes pledging adherence to the tribunal's rulings took place in cities including Warsaw, Lodz, Poznan, Bydgoszcz, Koszalin and Slupsk. That put the councilors at odds with provincial governors, who represent the ruling party.

The Supreme Court has also urged Poland's judges to follow the verdicts of the tribunal.

On Thursday, President Andrzej Duda appointed Judge Zbigniew Jedrzejewski to the already overpopulated tribunal where three vacancies have been claimed by both the government and the opposition. Duda insisted the new appointment was in line with the Constitution and expressed the will of the voters who have given Law and Justice control of the government, the presidency and the parliament.

The ruling party wants to have influence over the constitutional court to prevent it from blocking new legislation that the party is pushing as it is planning a wide reform of the state. But its moves have provoked an outcry from the opposition and from some European Union leaders who say that Poland's democracy and the rule of law are threatened.

Members of the Venice Commission, a European human rights watchdog, opened a two-day visit to Warsaw on Thursday. The commission is checking whether a law adopted in January that widens the scope of police surveillance of citizens is in line with the constitution and European standards.