Poland has been fined €1m (£845,000) a day by the European court of justice for ignoring a ruling that it must suspend its controversial judicial system changes. The inflammatory move, which runs contrary to recent words of caution from the German chancellor, Angela Merkel, was immediately denounced in Warsaw as “blackmail”. The development comes in the wake of a long-running battle between Brussels and Poland over changes that are said by critics to undermine the independence of the country’s judiciary. Poland’s prime minister, Mateusz Morawiecki, has warned that any move to implement calls from some member states to cut EU funding over the changes and the recent decision by the country’s constitutional court that ECJ rulings in some areas are not binding would “start world war three”. In the ECJ’s order on Wednesday, Poland was told it must pay €1m each day to the European Commission as a fine. Should Poland refuse to pay the fines, they will continue to stack up. The court also has the power to increase the size of the financial penalties. It said that suspending contested provisions as demanded by the ECJ – including changes to a disciplinary tribunal for judges deemed to compromise judicial independence – “is necessary in order to avoid serious and irreparable harm to the legal order of the European Union and to the values on which that union is founded, in particular that of the rule of law”. In response, Sebastian Kaleta, Poland’s deputy justice minister, said the ruling “completely disregards and ignores the Polish constitution and the rulings of the Polish constitutional tribunal”. He tweeted: “It is acting beyond its competences, and abusing the institution of financial penalties and interim measures. This is the latest step of an operation aimed at detaching from Poland influence on the system of our state. It is usurpation and blackmail.” At a summit in Brussels last week, EU leaders debated Poland’s rule of law crisis, with some member states calling for the withholding of €36bn-worth of funds due to Warsaw as part of the bloc’s pandemic recovery fund. Morawiecki has described such threats as “a gun to our head”. The EU’s top court has also imposed daily fines of €500,000 on Poland for refusing to suspend operations at its Turow mine in southern Poland over its environmental impact. “The road of penalties and blackmail against our country is not the right one,” Polish government spokesperson Piotr Müller tweeted. “This is not the model in which the European Union – a union of sovereign states – should operate.” The commission is expected to seek payment immediately. Last week, Merkel, at what is expected to be her final EU summit, warned her fellow leaders to be careful in their dealings with Poland, adding that there were fundamental issues that needed resolving. She said: “It’s the question of how the individual members envision the EU. Is it an ever closer union or is it more nation state? And this is certainly not only an issue between Poland and the EU, but also in other member states.”