Tomasz Grodzki represents the liberal opposition party Medborgarplattformen.
He made an unusual appearance for a President, saying that the right-wing government's veto, which stopped the EU's budget work, was not in Poland's economic or political interest.
The speech has been broadcast on all the country's major TV channels.
"If you make Poland lose huge sums of money for further development and reconstruction, and if you lead us out of our European home, history and the people will not forgive you," Grodzki said.
Poland maintains a budgetary veto with Hungary, as it opposes the conditionality of economic resources and special pandemic support based on the rule of law and demands for democracy.
The countries' respective right-wing governments have long been criticized for revolutionary legal reforms and power ambitions.
At the same time, Poland is one of the largest net recipients of economic funds in the EU and Hungary is not far behind.
-The government has no mandate to lead us out of the EU without asking the people what they think, says Tomasz Grodzki.