Hundreds of protesters chanting “Kiev, rise up!” have blocked Ukrainian police as they tried to arrest former Georgian president Mikheil Saakashvili.

He later escaped with help from supporters and led them on a march towards parliament, where they planned to call for President Petro Poroshenko to resign.

The detention of Mr Saakashvili, now an anti-corruption crusader in his adopted home, has raised fears that Ukraine could be facing its most acute political crisis since the 2014 revolution.

Ukrainian prosecutors accuse him of colluding with Ukrainian businessmen who have ties to Russian intelligence as part of an effort to topple the president.

Mr Saakashvili poses a threat to Mr Poroshenko, who appointed him as governor of Ukraine’s Odessa region before the two had a falling out.

In 2016 Mr Saakashvili resigned, complaining that his efforts to root out corruption were being obstructed by officials.

When the SBU, Ukraine’s Security Service, went to detain Mr Saakashvili at his home in Kiev yesterday, he climbed on to the roof.

SBU officers went after him, detained him and led him to a waiting van.

Hundreds of supporters surrounded the van, refusing to let it drive off.

After Mr Saakashvili escaped, he told his supporters that he would “lay down his life for the freedom of Ukraine” and called on them to follow him to the Supreme Rada.

Prosecutors plan to ask the court to place Mr Saakashvili under house arrest.