"The president lost the chance to behave like a patriot. Shame,” Tusk wrote on X shortly after Nawrocki announced his decision in a televised address.
The prime minister said the government would respond to the veto at an extraordinary meeting scheduled for Friday morning.
The law vetoed by Nawrocki would have created a security financing mechanism managed by state-run Bank Gospodarstwa Krajowego, through which the Polish government could access funds from the EU’s SAFE programme, which offers low-interest loans to help member states quickly strengthen their defence capabilities.
In his address, Nawrocki said he would not sign legislation allowing Poland to take out SAFE loans, arguing that such borrowing could undermine the country’s sovereignty and economic security.
Government officials have said the presidential veto would not prevent Poland from accessing SAFE funds, although it could complicate financing for services such as the Border Guard and police.
Poland was expected to be the largest beneficiary of the programme, potentially receiving about EUR 43.7 billion in loans for defence projects.