WARSAW, 20 October 2021, (TON): The ferocious row, played out in the European Parliament, underlined the seriousness of the issue which both Brussels and Warsaw say threatens the cohesion of the 27-nation bloc.

Polish Prime Minister Mateusz Morawiecki accused the EU of "blackmail" on Tuesday in a public clash with European Commission chief Ursula von der Leyen over his country's rejection of parts of EU law.

The ferocious row, played out in the European Parliament, underlined the seriousness of the issue which both Brussels and Warsaw say threatens the cohesion of the 27-nation bloc.

Von der Leyen, speaking just before and after Morawiecki took the podium, warned that her Commission -- tasked as guardian of the EU treaties -- "will act" to rein in Poland.

She said a controversial October 7 ruling by Poland's Constitutional Court challenging the primacy of EU law was an attempt "to take an axe to the European treaties by undermining their legitimacy."

She said "undermining any of these essential pillars puts our European democracy at risk. We cannot let this happen. We will not let this happen.”

Von der Leyen spoke of a number of legal, financial and political options being considered, adding that "the rule of law and the treaties of the European Union are to be defended with all instruments at our disposal".

Morawiecki, in a long speech, hit back by saying "I will not have EU politicians blackmail Poland."