Twitter has refused to talk to an MP about his experience of neo-Nazi cyber-hate despite him travelling to Dublin to speak to the social media company this week.
Labour MP John Mann said the internet giant's representatives would not discuss the abuse he had suffered.
During a meeting at Twitter's European head office, he cited examples of antisemitic tweets directed at his colleague, Jewish MP Luciana Berger, and the subsequent attacks he faced from racist users of the site when he defended her.
But Mr Mann said the company would not address his concerns: "They held the unprecedented position of refusing to discuss specific cases, even though the specific case in question related to me and I was in the room."
He left the meeting feeling "underwhelmed" and "exasperated" after the internet firm gave conflicting information about its policies on handing over information about abuse to police.
Writing in today's JC, Mr Mann explained: "The approach of some of those at Twitter was churlish, belligerent and illogical. We were forced into debating high-level policy positions without the use of examples."
Its bosses were less progressive than competitors such as Facebook, which had shown signs of working to improve its systems for detecting abuse, Mr Mann said.
Twitter executives were "rude" and "unhelpful" throughout the meeting, the JC understands. A source close to the discussions said the meeting had been demoralising: "What can we do? Do we wait for them to work it out or for something so terrible to happen that they are forced to act?
Mr Mann is chair of the All-Party Parliamentary Group Against Antisemitism which is conducting an inquiry into the surge in racial hatred and violence during the Gaza conflict this summer. A report will be published early next year.
Mr Mann led a delegation to Amsterdam last week to meet the city's mayor and take advice on how police can challenge hatred against Jews.
