Conservative Friends of Israel chairman Sir Eric Pickles has expressed his “shock” at comments from Labour councillors in Leicester comparing Israeli Prime Minister Benjamin Netanyahu to Adolf Hitler.

In a letter to Leicester’s mayor Sir Peter Soulsby, sent on Tuesday, Pickles describes how other councillors have in the past said Britain sponsors “Jewish colonial immigration” and compared Israel to Apartheid South Africa.

“It was with real shock that I came across a number of statements by your Labour councillors which are a real concern,” he said. “I am sure many in the Jewish community would find these comments unacceptable.”

None of the comments Pickles mentions were made in the last two years, with some dating back to 2012, and his intervention follows a recommendation by former Liberty director Shami Chakrabarti that a line be drawn under past comments made by Labour members.

Leicester City Council was one of three local authorities accused of anti-Semitism for instituting a boycott of Israeli goods and services from the West Bank in the wake of the Gaza conflict in 2014, in a motion proposed by Cllr Mohammed Dawoob.

In his letter to Soulsby, Pickles said that a year earlier, in 2013, Dawoob said Britain sponsored “Jewish colonial immigration” to Palestine from 1918 to 1948, and that in 2012 he compared Israeli policies to apartheid.

A legal challenge for discrimination, brought against Leicester’s boycott by Jewish Human Rights Watch last year, was unsuccessful in the High Court.