Poland politicians issue protest letter in court row
Presidents are among former leaders in Poland expressing concern at attempts by the ruling Law and Justice party (PiS) to increase its influence over the country's Constitutional Court.
Fifteen officials issued an open letter voicing "anxiety and opposition".
The PiS has appointed five loyal judges to the 15-member court in a move it says is aimed at tackling cronyism.
The head of the European Parliament, Martin Schulz, has compared events in the country to a "coup d'etat".
Poland's Prime Minister, Beata Szydlo, called Mr Schulz's words "unacceptable" and demanded an apology.
Thousands of people marched through Warsaw to show support for the right-wing PiS on Sunday following anti-government protests on Saturday.
Critics accuse Poland's government of trying to manipulate state institutions.
Former Prime Minister Ewa Kopacz, from Civic Platform (PO), as well as former Presidents Bronislaw Komorowski and Aleksander Kwasniewski, were among the signatories of the letter published on Tuesday.
They said they were seeking to defend the court's role in upholding the constitutionality of the country's new laws.
Led by Jaroslaw Kaczynski, the Eurosceptic PiS has accused the court of blocking its policies.
The party has regularly come to blows with the media and the opposition since it came to power in October.
Relations with the European Union have also been strained, with Poland agreeing to financially support EU efforts to alleviate the migrants crisis but refusing to take in asylum seekers.
In an interview with German newspaper Berliner Zeitung, Poland's Foreign Minister Witold Waszczykowski lashed out at Germany over claims Poland had failed to show "solidarity" in the crisis.
He also complained that Nato had not stationed a unit in Poland, saying it was "because Germany cares more for the interests of Russia than the security interests of central-eastern Europe".