Ken Livingstone has claimed there was at one point “real collaboration” between the Nazis and Jews, ahead of a hearing concerned with whether he has brought the Labour party into disrepute.

The former London mayor made the fresh series of highly controversial remarks before the start of an internal party tribunal that is hearing evidence about his suspension from the Labour party a year ago.

Livingstone’s comments expanded on his claim that Hitler supported Zionism because the Nazi government signed the Haavara agreement, which facilitated the relocation of Jews to Palestine in 1933 before the Third Reich turned to mass murder and extermination. The agreement allowed a portion of Jewish emigrants’ possessions, which they were forced to hand over before they left Germany, to be re-claimed through transfers to Palestine as German export goods.

Referring to Hitler, Livingstone said: “He didn’t just sign the deal. The SS set up training camps so that German Jews who were going to go there could be trained to cope with a very different sort of country when they got there. When the Zionist movement asked, would the Nazi government stop a Jewish rabbi doing their sermons in Yiddish and make them do it in Hebrew, he agreed to that.

“He passed a law saying the Zionist flag and the swastika were the only flags that could be flown in Germany. An awful lot. Of course, they started selling Mauser pistols to the underground Jewish army. So you had right up until the start of the second world war real collaboration.”

He also claimed that when senior Nazis objected to sending Jews to Palestine in case it created a Jewish state, a directive came from Hitler ordering them to continue with the policy.

Livingstone was originally suspended “for bringing the party into disrepute” after MPs accused of him of antisemitism and making offensive comments about Hitler supporting Zionism.

More than 20 MPs, including Sadiq Khan, the London mayor, had called for Livingstone to be expelled over the remarks he made while trying to defend the suspended Bradford MP Naz Shah.

Outside the tribunal, Livingstone claimed the Labour party was no longer investigating him over antisemitism or the claim that Hitler was a Zionist, but focusing on the accusation that his defence of Shah had brought the party into disrepute.

Shah’s suspension was lifted after she issued an apology over historic Facebook posts that suggested Israelis be deported to the US.

Livingstone said: “It’s completely unfair. We have a tradition of law and that is open. There’s absolutely no justification for something like this being done in private. They have dropped all the charges that I’m antisemitic. They’ve dropped the charge that I said Hitler was a Zionist.

“It’s really coming down to claiming I brought the party into disrepute by defending Naz Shah. As she’s been readmitted to the party that does seem a bit excessive to try and expel me for supporting her.”