During a debate at the European Parliament in Strasbourg on Tuesday, Mateusz Morawiecki said that "politics must be based upon principles."
Morawiecki had travelled to France to take part in a debate on a ruling by Poland’s Constitutional Tribunal, which challenged the supremacy of EU law over national law.
The ruling increased tensions between Warsaw and Brussels and led to calls that EU funding should be withheld from Poland until it changes tack over a serious of changes to the country’s judicial system that some claim undermine the rule of law.
The Polish government has described the threat to hold funding back as blackmail.
"Democracy is a principle that is adhered to in Poland, and this is what the European Union is based on," said Morawiecki. "And this is why we cannot remain silent when our country, as it is here, is attacked in an unjust and biased manner."
The prime minister said that "the rules of the game must be the same for everyone" and added that "the duty of all, including the institutions established in these treaties, is to observe them. This is what the rule of law depends on."
"It is unacceptable to impose your decision on others without a legal basis," he continued. "It is all the more unacceptable to use the language of financial blackmail for this purpose, to talk about penalties or to use words that go even further against some member states."
He added: "I reject the language of threats and extortion. I do not agree to Poland being blackmailed and threatened by politicians - so that blackmail does not become a method of conducting politics towards one of the member states. This is not how democracies work."
"We are a proud country, Poland is one of the countries with the longest history of statehood and development of democracy," he said.
The prime minister also told the parliament that, today, when the level of trust towards the European Union has fallen to historically low levels, "over 85 percent of Polish citizens clearly state that Poland is and will remain a member of the Union."
Morawiecki added: "My government, the parliamentary majority which stands behind this government, is a part of this pro-European majority in Poland."
"This does not mean that Poles today are not experiencing doubts and anxieties about the direction of changes taking place in Europe. This anxiety is visible and, unfortunately, justified," said the prime minister.
"I spoke about how much Poland had contributed to the EU but, unfortunately, we are constantly hearing about the division into those who are better and worse. Too often we are dealing with a Europe of double standards," he added.
According to Morawiecki, this type of model must come to an end.
He noted that all Europeans expect to face challenges together and not to work against each by looking for someone who is "convenient to blame."
During Tuesday's debate, the prime minister also proposed that an additional chamber be added to the Court of Justice of the European Union consisting of judges elected by the constitutional courts of EU countries.
Morawiecki added that EU laws take precedence over national laws, but not over constitutions.
The prime minister also said that Russia had a role in the worsening European energy crisis which, as he assessed, may contribute to the bankruptcy of some European companies and, as a result, create a "domino effect" that triggers further crises. (PAP)