The Czech government has formally excluded President Petr Pavel from the national delegation attending the NATO summit in Ankara this July.
The decision, announced on Monday, marks a sharp escalation in the ongoing power struggle between the presidency and the prime minister's office over foreign policy authority.
President Pavel has responded by filing a petition with the Czech Constitutional Court, seeking a ruling on the legality of the government's move.
The legal challenge underscores the deepening institutional rift in Prague, which risks projecting disunity at a critical alliance gathering.
The conflict centers on the division of competencies regarding international representation.
While the government asserts its right to determine the composition of the delegation, the presidency argues that the head of state holds a constitutional role in foreign affairs.