The defection of English Defence League founder Tommy Robinson is unconvincing and does not remove the threat posed by the group’s supporters, Anglo-Jewry’s most senior security expert has warned.

Richard Benson, who left his role as chief executive of the Community Security Trust last month, said Mr Robinson was “a street thug” who was yet to prove himself a reformed character.

In his first interview since leaving CST after 12 years at the helm, Mr Benson said he was proud of the role the charity had played in tackling the EDL. CST repeatedly warned the Jewish community against supporting the extreme right-wing anti-Islamist group after Mr Robinson’s supporters launched a “Jewish division” three years ago.

Mr Robinson announced he was leaving the EDL a fortnight ago after working with the counter-extremism group, the Quilliam Foundation. But Mr Benson said he was unconvinced by the decision.

“I still find it a bit confusing. It doesn’t add up. When you listen to Robinson now, he still doesn’t go down the path of being moderate. He isn’t saying he doesn’t have an issue with Muslims.

Tommy Robinson hasn’t yet said anything that leads us to believe that he has changed

“He is an absolute street thug, but sometimes when you listen to him he comes over as quite articulate. The problem is he hasn’t yet said or done anything that leads us to believe he has changed.”

Mr Robinson was jailed for assault in 2005, and has previous convictions for drug and public order offences and possession of a false identity document.

Reflecting on the development of CST over the past decade, Mr Benson described his satisfaction at the charity becoming a leading organisation in British Jewry, and predicted a bright future for the community.

A potential merger of the Board of Deputies and Jewish Leadership Council should “absolutely” go ahead and was a “natural progression”, he said. “It makes sense that the community has the space for both the grassroots and the senior leadership to come together in different ways. I think in the best interests of our community, having them as one is important.”

Mr Benson is the latest senior communal figure to leave his role this year, following the departures of Jon Benjamin and Jeremy Newmark from their positions as chief executives of the Board and JLC respectively. Replacements for the latter two have yet to be announced.

But Mr Benson said the changes should not lead to fears of a leadership “vacuum”.

“Jon, Jeremy and I sat at meetings alongside each other, we used to meet officials in Downing Street together, we sat on parliamentary committees and taskforces together.

“As a triple-act it meant we became all-powerful on community issues. When there were big events taking place we were brought in.

“But one of the strengths of this community is that we have fantastic lay leadership and professional training programmes. Looking at the next generation, I see it as a great opportunity to allow people to move up.”

Mr Benson’s successor, David Delew, was appointed after successfully leading CST’s operations in Manchester.

Mr Benson also offered a robust defence of the roles played in the community by CST chairman Gerald Ronson and JLC chairman Mick Davis.

Criticising attacks on the JLC, he said: “To say that it is full of money men who want to control the community is wrong and insulting. People like Mick and Gerald are deeply committed in terms of their time and money.”

It was not true, he said, that wealthy individuals had “bought” their communal leadership positions, but rather they had earned them through decades of service. “Their records speak for themselves. When you hear the comments made about them — it’s wrong.”

Mr Benson said the threat of antisemitic violence targeting British Jews had given him many sleepless nights over the years. The greatest threat had come in 1999, when neo-Nazi David Copeland carried out a 13-day bombing campaign against minority communities.

“We honestly believed that we were going to be his next target,” said Mr Benson. “When he was finally arrested and they looked at his list, the Jewish community was on it. The concern for me was that I was asking volunteers and staff to go on the streets, work alongside police officers, and God forbid something could have happened.”

The past four years had been “intense” due to the number of terrorist cases featuring British Jews as targets. Oldham couple Mohammed Sajid Khan and Shasta Khan were the embodiment of one of CST’s greatest fears — an unknown pair who avoided detection until the last moment. In a separate incident in 2010, a terror gang targeted two rabbis for assassination and their synagogues for bombing.

Mr Benson said: “The day the Khans were arrested we were contacted by the police — they had found a list of Jewish locations. The Khans were completely under the radar. That’s why we continuously do our research work.

“Every time the community has been targeted, CST has had a phone call from the police, and they have said: ‘This is what we’ve got, we need to work together’. The good relationship we have pays off in the end.”

Mr Benson said CST had worked more closely with government following the September 11 terror attacks. A funding agreement which sees £2.3 million provided by the government for security measures at 43 Jewish state schools was evidence of the strength of the relationship, he said.

During his time at CST, Mr Benson worked with every Home Secretary, but said the charity had at first struggled to convince ministers of the need for assistance. “We had one meeting where Charles Clarke wasn’t able to get his head round it. We were sitting in our office and thought ‘hang on a minute, not all our buildings are private — we have schools, they are state-funded’.

“It was a light-bulb moment. Gerald [Ronson] and I went to see Ed Balls when he was Education Secretary and we said ‘here’s an alternative’.”

The current Education Secretary, Michael Gove, agreed to continue the arrangement. “The challenge we have is that the contract expires in 2015,” said Mr Benson.

Such relationships in Westminster have also attracted fierce criticism. CST’s work with current Home Secretary Theresa May over blood-libel cleric Sheikh Raed Salah saw it attacked by left-wing media and anti-Israel activists.

“The report we provided became public and we came in for a beating, people saying we were going above our remit. We felt we had done nothing wrong.

“Our position was that if we wanted the community to be safe, it wasn’t just about putting people on guard at the front door. It is also about legislation focused on the community. To achieve that you need to be speaking to the government.

“We know there are organisations that want to undermine us. So be it. But we as a community have always punched above our weight.”