The Kremlin has not commented but Western intelligence services have previously said that dozens of assassination attempts against Mr Zelensky have been foiled. In May, the SBU arrested two Ukrainian colonels working in the military unit tasked with protecting top officials for plotting to kill Mr Zelensky. They had planned to kidnap the Ukrainian president and then execute him.

Sunday’s alleged coup plot appears to have been bigger in scope than the May assassination plan. The SBU said that as well as mobilising in Kyiv, the coup plotters had grassroots organisations in Dnipro and other Ukrainian cities.

“They communicated with each other in various instant messengers and, if they met, they did so in small groups of three,” said the SBU.

It also released, as evidence of the plot, an alleged voice recording of a conversation between two coup leaders. In the recording, one of the coup leaders claims to have the support of “not hundreds, but thousands” of people.

“We are officially going to organise ourselves as a Veche,” the leader said, using the word for a council or assembly in medieval Slavic city states. “We need to gather as many people as possible.”

The SBU said that if the alleged plotters are convicted, they could be sentenced to prison for up to 10 years.

Ukrainian intelligence services have warned this year that the Kremlin has stepped up its plots against the Ukrainian government as well as schemes to destabilise Ukraine.

Western governments have also warned that Kremlin agents have become more active in Europe.