A senior director of an influential thinktank has defended a Labour councillor accused of antisemitism and backed her claim Mossad is involved in a campaign to prevent Jeremy Corbyn becoming prime minister.

Willie Sullivan – who works at the Electoral Reform Society which aims to change the way voting takes place at elections in the UK -  made his controversial remarks after coming to the defence of Scottish Labour councillor Mary Lockhart after she suggested there was a “Mossad assisted campaign to prevent the election of a Labour Government.”

Writing on Facebook, Mr Sullivan, who is listed on the official ERS website as Senior Director ERS Scotland and Campaigns said: "What! You seriously don't believe that the state of Israel and its security services are willing to intervene to prevent a pro-Palestine P.M.

“That is... Somewhat like the idea that Russian state or the British state security services do not make strategic security interventions in other countries.”

On Monday a spokesperson for the ERS confirmed to the JC they were now investigating Mr Sullivan's comments.

"We are an equal opportunities employer and take any allegations of this nature seriously,” the spokesperson added.

Mr Sullivan was responding after another Labour Party member Michael McMahon criticised Ms Lockhart's Mossad remarks.

After someone said Israel was not responsible for the antisemitic actions of party members, Mr Sullivan said: "Both can be true. There can be people who are racist and antisemitic in the Labour party. And Israel state security services will be interested in whether the UK has a pro-Palestine PM.

“And most people who know anything about this would be surprised if they did not consider tactical interventions to increase the likelihood of outcomes in the interest of Israel. That is their job."

He said to deny this was "either deeply niave or is itself a political position/tactic.”

He later added: "What seems clear is that there are some antisemitic nasties in the Labour Party.

"There are also some people in the Labour Party who would rather destroy it than see Corbyn as PM. They see their career paths cut off by him and they have many other reasons for hating him some of which are to do with his position on Palestine."

Ms Lockhart made her Mossad remarks in response to three Jewish newspapers, including the JC, taking the unprecedented step of publishing the same front page condemning antisemitism within Labour.

Ms Lockhart, who is a Fife councillor, wrote: “If the purpose is to generate opposition to antisemitism, it has backfired spectacularly.

“If it is to get rid of Jeremy Corbyn as Labour Leader, it is unlikely to succeed, and is a shameless piece of cynical opportunism.

“And if it is a Mossad [the Israeli secret service] assisted campaign to prevent the election of a Labour Government pledged to recognise Palestine as a State, it is unacceptable interference in the democracy of Britain.”

Former Dunfermline and West Fife Labour MP Thomas Docherty said he would be making a formal complaint about Ms Lockhart.

He said: “If you even suggest that British Jews are agents of the Israeli secret service, that is an antisemitic trope and you have no place in the Labour Party.”

In 2016, Ms Lockhart apologised for any offence caused by a social media post which appeared to compare some Labour officials to Nazis.

She referred to a famous poem about persecution in the Third Reich when protesting against a decision to ban some Labour members from the UK leadership contest.

The ERS has been involved in numerous high profile campaigns – including a referendum on the voting system in the wake of the United Kingdom parliamentary expenses scandal as part of the Vote for a Change campaign. It is a founding member of the Votes at 16 Coalition.

After the JC contacted Mr Sullivan he said:"“I want to be clear that conflation between the actions of the state of Israel and the Jewish people is wrong and deeply misleading.

My comments were solely about the actions of the state of Israel. I can understand that in the context this may have been unclear. If this has caused any office or hurt then I apologise wholeheartedly.”