Israeli Arab Knesset members have launched a blistering attack on the Jewish state and its Parliament, declaring Israel "racist, fascist and worse than apartheid South Africa".
Speaking to supporters of the Palestine Solidarity Campaign at the House of Commons on Wednesday, MK Haneen Zoubi said: "Israel is much worse than the apartheid regime in South Africa. There were no ethnic cleansing policies there, but there are those policies in Israel."
Demand for entrance to the event was so great that supporters filled two committee rooms.
One campaigner said the current Palestinian mood lent itself to a third intifada, an "intifada for democracy".
In May Ms Zoubi, 41, was on the lead boat in the Gaza flotilla and addressed the Knesset by phone while on board. She was interrupted with shouts of "Go to Gaza, traitor" by Jewish MKs.
Speaking at the PSC event she said: "Everyone in Europe who supports Israel, financially and politically, must know they also support its racism, oppression, occupation and siege.
"The racism and discrimination against Palestinians in Israel is systematic. It's not a policy, it's an ideology. No-one can support the siege and call themselves a human being."
Ms Zoubi attacked Israeli Foreign Minister Avigdor Lieberman's proposal to require all new Israeli citizens to swear an oath of allegiance recognising the country as a Jewish state.
She said she would campaign for democracy for "Palestinians, Israeli Arabs and Israeli Jews" alike.
Jamal Zahalka, an MK since 2003, said the Knesset had passed "racist laws" that discriminated against Israeli Arabs.
"There is democracy, and then there is Israeli democracy," he said. "I say, give me my land and keep your 'democracy'. We should focus on the end of the occupation, the end of the siege and the end of the settlements. A two-state solution is losing time and becoming impractical."
Members of Jews for Justice for Palestinians attended the event, co-organised by the Middle East Monitor group.
Labour's Islington North MP Jeremy Corbyn, who chaired the meeting, said: "It's wonderful to have guests here who have first-hand knowledge of being Arabs living in Israel - and being Knesset members and having the experience of all the problems that come with that."
Betty Hunter, PSC general secretary, said: "This is a landmark event. It's important to have these MKs here to tell us that there is no democracy in Israel, and to tell the world about the reality of Israeli oppression. The lie that Israel is a democratic state must be smashed."