Two radical anti-Israel activists have been banned from entering the German parliament building for chasing a senior left-wing politician into a lavatory after he cancelled a meeting with them.

The pair – American Max Blumenthal and Canadian-Israeli David Sheen – were invited to the Reichstag by members of the socialist Left party. But the party’s head Gregor Gysi, himself a critic of Israel, cancelled the meeting due to their “radical” views, according to a party spokesman.

After learning of the ban Blumenthal and Sheen confronted Gysi, chasing him down a corridor when he refused to engage with them. In at least two videos of the bizarre encounter posted on Youtube, Sheen can be heard accusing Gysi of calling him an “anti-Semite” – an accusation Left Party spokesman Hendrik Thalheim denied in an interview with Bloomberg.

The men chased Gysi into a bathroom and even forcibly prevented him from closing the door at one point; Gysi responded by shouting “get out of here!” and refusing to engage with them.

The display of intimidation apparently appalled even some of those who invited the two extremists, with one woman breaking up the confrontation and telling them “that’s not the way we do things here.”

As a result of the confrontation, both Sheen and Blumenthal are now the German parliament.

“Every attempt to exert pressure on members of parliament, to physically threaten them and thus endanger the parliamentary process is intolerable and must be prevented,” the chamber’s president, Norbert Lammert, said in an emailed statement.

Watch – anti-Israel activists chase German MP