Debate began on Tuesday in the Czech lower house of parliament over a no-confidence motion against the right-wing government that came to power only in December.
The move was described as a “necessary and logical step” by Martin Kupka, leader of the largest opposition force, the Civic Democratic Party.
The trigger for the motion is alleged threatening text messages sent by newly appointed Foreign Minister Petr Macinka to President Petr Pavel.
The politician from the right-wing, eurosceptic Motorists party is accused of attempting to force the appointment of his party colleague Filip Turek as environment minister.
Pavel had questioned the suitability of the 40-year-old Turek for a ministerial post due to past remarks that many viewed as racist and sexist.
On Sunday, tens of thousands of people took to the streets in Prague to show solidarity with Pavel, a former senior NATO commander seen as staunchly pro-Western. Organizers said up to 90,000 people attended the demonstration.
Andrej Babiš, the billionaire tycoon who returned as prime minister in December, criticized the no-confidence debate as a waste of time.
“This is yet another attempt to feed people nonsense,” said the founder of the right-wing populist ANO party. “They should finally let us get on with our work,” he demanded of the opposition.
The vote on the no-confidence motion has not yet been scheduled. It is seen as unlikely that it will secure a majority.
A total of 101 votes would be required, while the three-party governing coalition currently holds 108 of the 200 seats in the Chamber of Deputies.