The conflict is partly about support for Ukraine and partly about the president's refusal to appoint as environment minister a politician who is being investigated for rape, among other things. The politician belongs to the Motorists party, which is part of Prime Minister Andrej Babiš's government coalition.
On Tuesday, President Petr Pavel published images of messages in which the Czech foreign minister threatened revenge if President Petr Pavel did not agree to the appointment.
According to an independent organization, around 90,000 people participated in the demonstrations.
"We are here to show the president that he is not alone. The devil of dictatorship never sleeps and we must be on our guard," one protester told AFP.
