Hungary's justice minister has slammed the European Union for pushing to impose fines on Poland over judicial reforms.
Judit Varga has accused Brussels of "attacking" Warsaw and intervening in a country's legislative process.
The European Commission said on Tuesday it had asked the EU's Court of Justice to impose daily fines on Poland.
The bloc has been engaged in a dispute with Warsaw over the rule of law and a controversial chamber of the Polish Supreme Court that disciplines judges and prosecutors.
Brussels sees the chamber as a threat to the country's judicial independence that makes judges subject to political control.
And even though the Polish government said it would dismantle the chamber, the European Commission has stated that "not taken all the measures necessary" have been taken.
On Wednesday, Varga said that the EU was "scandalous and arrogant" for ignoring Poland's pledge.
"The European Commission made a rude attack on Poland," the justice minister said in a post on Facebook.
"The procedure is not only outrageous but also completely unacceptable ... With this scandalous and arrogant step, the Commission crossed a border that we previously thought was unimaginable," she added.
"We broadly endorse Poland and show solidarity with our Polish friends," Varga continued.
Poland's Deputy Justice Minister Sebastian Kaleta has also described Brussels' move to request daily fines as "aggression".
The two EU member states have been key allies in recent years, and have previously locked horns with Brussels over press freedoms and LGBT rights.
Hungarian Prime Minister Viktor Orban also assured Polish President Andrzej Duda that Budapest would give "solidarity and full support" to Warsaw at a meeting on Thursday.
Orban said that Brussels is "abusing its power" and labelled the fine "outrageous and completely unacceptable," according to his press secretary.