BRUSSELS (Reuters) - The European Commission notified Poland on Tuesday it would withhold cash that the EU was to pay Warsaw as part of regular EU transfers, to cover the first part of fines imposed by the EU's court on Poland which the country did not pay.

       This is the first time that the Commission has to withhold EU money for a member country because it is not complying with a ruling by the EU's top court.

       Last September, the Court of Justice of the European Union put a 500,000 euro ($571,000) daily fine on Poland for not stopping the operations of its Turow lignite mine and power plant on the border with Czech Republic.

       This followed a complaint from Prague that its operations were endangering water sources of residents across the border. Poland's eurosceptic and nationalist government refused to comply with the court ruling.

       "The Commission has informed Poland that it would proceed with the offsetting of payments for penalties due under case C-121/21 Czechia v Poland on Turów lignite mine", Commission spokesman Balazs Ujvari said in a statement.

       "The offsetting is for penalties covering the period 20/9/2021-19/10/2021", the statement said.

       An EU official said the amount withheld to cover the fines for that period was around 15 million euros.

       "The Commission will proceed with the offsetting after 10 working days from this notification", Ujvari said.

       ($1 = 0.8757 euros)

       (Reporting by Jan Strupczewski)