Jeremy Corbyn’s newly formed Left-wing party faced significant turmoil today after a co-founder accused the group of being a ‘sexist boys’ club’ and alleged her exclusion from major decisions.

Zarah Sultana, the MP for Coventry South assisting Mr. Corbyn in establishing his Your Party initiative, expressed her grievances in a sharply worded statement, claiming she had been treated ‘appallingly’.

The intense dispute erupted following an ‘unauthorised email’ sent out to supporters of Your Party, which Mr. Corbyn said encouraged them to register for membership without prior approval.

Ms Sultana had encouraged supporters to pay up to £55 per year for a year’s membership via a link included in the email.

But, hours later, Mr Corbyn issued an ‘urgent message’ telling supporters to immediately cancel any direct debits.

The statement was signed by Mr Corbyn and the four other members of his ‘Independent Alliance’ of MPs, who are also helping to found Your Party.

They revealed they were taking legal advice and said the ‘unauthorised email’ sent this morning ‘should be ignored by all supporters’.

Yet, Ms Sultana insisted it was a ‘safe, secure, legitimate portal’ as she urged supporters to ‘sign up now’.

Ms. Sultana remarked, ‘After being pushed aside by the MPs identified in today’s statement and effectively shut out from official communications, I initiated the launch of a membership portal to ensure supporters could still engage and organize.’

‘This was in line with the roadmap set out to members on Monday and is a safe, secure, legitimate portal for the party. Everyone who supports us should sign up now.

‘My sole motivation has been to safeguard the grassroots involvement that is essential to building this party.

‘Unfortunately, I have been subjected to what can only be described as a sexist boys’ club.

‘I have been treated appallingly and excluded completely. They have refused to allow any other women with voting rights on the Working Group, blocking the gender-balanced committee that both Jeremy and I signed up to.’

Ms Sultana called for Mr Corbyn to ‘meet with me’ in a bid to ‘ensure nothing like this can ever happen again’.

‘This party is more important than any one person, and we owe it to the movement to deliver a truly democratic and socialist party,’ she added.

‘No stitch-ups, no coronations: the members must decide.’

She also revealed that ‘neither of this week’s emails had the dual authorisation of both myself and Jeremy – which was the agreement made at the start of this process’.

Ms Sultana shared her statement on social media shortly after Mr Corbyn posted his ‘urgent message’ to Your Party supporters around 2pm on Thursday.

The statement was also signed by his fellow ‘Independent Alliance’ MPs; Ayoub Khan, Adnan Hussain, Iqbal Mohamed, and Shockat Adam.

It read: ‘This morning, an unauthorised email was sent to all yourparty.uk supporters with details of a supposed membership portal hosted in a new domain name.

‘Legal advice is being taken. That email should be ignored by all supporters. If any direct debits have been set up, they should be immediately cancelled.’

It is the latest sign of bitter division among Left-wingers in their efforts to set up a rival party to Labour.

Ms Sultana and Mr Corbyn’s movement has the website yourparty.uk, with a welcome message saying ‘this is your party’.

But Ms Sultana sowed confusion immediately after its launch in July by insisting a name had not yet been chosen.

She frantically posted on social media: ‘It’s not called Your Party.’

It was explained that members would decide on the new party’s name at a later date, but political opponents mocked the ‘chaotic’ launch.

It followed claims Ms Sultana had previously caught Mr Corbyn by surprise by quitting Labour and publicly announcing their plans to found a new party.

Mr Corbyn last week insisted the launch of the new party was ‘not messy at all’ and ‘a totally coherent approach’.