The Labour Party has suspended the Brighton, Hove and District branch and annulled the election of a new executive committee.

Supporters of Jeremy Corbyn were elected to key posts at the local party’s annual general meeting (AGM) at City College, in Pelham Street, Brighton, on Saturday (9 July).

The branch is the biggest in the country with about 6,000 members – and more than 600 voted in the elections at the AGM which took place in three sittings to accommodate the large turnout.

Accusations have since been made about the conduct of some people at and after the meeting in what one member described as “tit-for-tat” claims.

Questions have been raised with the party about the integrity of the ballot on Saturday and safety at the crowded venue.

One complaint alleged that the Labour leader of Brighton and Hove City Council, Warren Morgan, had brought the party into disrepute over remarks that he made on Twitter about a “spitting” incident. Councillor Morgan is expected to dispute this.

The complaint against him was made shortly before 5.30pm today when the local party was formally suspended in a letter sent by Katherine Buckingham, the national party’s head of disputes and discipline. It seems unlikely that this complaint triggered the suspension.

The party was also asked to investigate whether the newly elected chairman of the local party, Mark Sandell, was ineligible because he used to be a member of the Alliance for Workers Liberty (AWL). The AWL has opposed Labour in the past.

Separately a local party activist told a Labour supporter, Seema Chandwani, who had come to Brighton for a “Keep Corbyn” rally on Saturday, to fuck off back to London. The abuse was said to have taken place in a pub close to Brighton Station as two councillors and a former local party executive committee member looked on.

The local party was suspended about 25 years ago when Steve Bassam was the leader of Brighton Borough Council. A number of people referred to as militants were purged, including six councillors.

Lord Bassam is now the party’s chief whip in the House of Lords although he is not currently attending shadow cabinet meetings in protest at the decision by Jeremy Corbyn not to resign after a vote of no confidence by MPs. He still lives locally.

Labour’s ruling National Executive Committee (NEC) has also suspended all constituency party meetings until the end of September – after the leadership contest is over.

A number of constituency parties are reported to be calling unofficial meetings. The suspended local party may do something similar in Hove on Tuesday (19 July).