Andrew Fisher, Jeremy Corbyn's head of policy, suspended by Labour Party

There is no known precedent for someone employed by a Labour Party leader to have his membership taken away

Labour party leader Jeremy Corbyn stands alongside Labour candidate Jim McMahon (Getty)

Jeremy Corbyn has suffered a humiliating blow to his authority within the Labour Party with the announcement that his policy adviser has had his party membership suspended pending an investigation.

Andrew Fisher, has been under fire since The Independent revealed that he had posted a series of messages on Twitter attacking the Labour leadership during Ed Miliband’s time.

Mr Corbyn is standing by his embattled adviser, who will carry on working in the leader’s office despite the suspension – though his position will be untenable if an investigation by the national executive results in his being expelled. There is no known precedent for someone employed by a Labour Party leader to have his party membership taken away, even temporarily. The setback is a graphic illustration that Jeremy Corbyn’s unexpected victory in the leadership election does not give him complete control over the party machinery. The decision to suspend his adviser was taken by the General Secretary, Iain McNicol.

Andrew Fisher has attracted criticism in the past for his tweets

The tweet that has done Mr Fisher the most harm in Labour circles was one which urged voters in Croydon Central to back an anarchist who was standing in the general election. He wrote: "FFS if you live in Croydon South, vote with dignity, vote campaignbeard" - a reference to the Twitter account of Class War candidate Jon Bigger. Emily Benn, who was Labour candidate in Croydon Central, has sent a written complaint to Mr McNicol.

In a letter to the General Secretary last week, Mr Fisher apologised for the tweet, which he said had been “misinterpreted” and “caused embarrassment.” The Shadow Chancellor John McDonnell, a Corbyn ally, has claimed that it was meant to be satirical.

Mr McNicol has also had a written complaint from a party member in Brighton about reports that Mr Fisher had encouraged voters there to back the Green MP Caroline Lucas. Under Labour Party rules, anyone supporting a rival from another party against a Labour candidate is liable to be expelled.

The complaints will be investigated by Labour’s National Executive Committee, who may also want to look at other tweets in which Mr Fisher described Ed Miliband’s shadow cabinet as “the most abject collection of absolute shite”, or in which he appeared to welcome the news that the former shadow Chancellor Ed Balls lost his Commons seat in the May election, saying it was "fitting that the architect of Labour's miserable austerity-lite economic policies should lose.”

At the time, Mr Fisher was working for Mark Serwotka, the head of the civil service union, the PCS, whose politics are left of the Labour Party’s, but was taken on by Jeremy Corbyn in September, after working over the summer on his election campaign.

As the suspension was announced, Mr Corbyn issued a statement saying: "I have full confidence in Andrew Fisher and his work. I respect the integrity of the General Secretary's office and trust that this matter will be settled as quickly as possible."

A Labour Party spokesman said: "Andrew Fisher has been suspended from the Labour Party. The NEC will now be asked to authorise a full report to be drawn up with recommendations for disciplinary action if appropriate."

Jeremy Corbyn was twice challenged about Mr Fisher during the weekly meeting of MPs. Yesterday, two MPs who took up the case, Caroline Flint and Siobhain McDonagh, issued a joint statement saying: "We are pleased that without fear or favour the Labour Party is enforcing its rules. These rules must apply equally to all members whether they deliver leaflets, are elected representatives or are staff in the Leader's office. On behalf of those hard working members who were offended by Mr Fisher's activities which included supporting a candidate against Labour in May, it is only right that the General Secretary has initiated an enquiry."