Leaders of staff involved in a long-running dispute over pay at the Picturehouse cinema chain have been suspended ahead of a fresh round of strikes. Six union officials at the Ritzy in Brixton and one at Hackney Picturehouse have been suspended, a move that the union Bectu has called “appalling”.

Staff at the Ritzy and five other Picturehouse cinemas have been taking industrial action for months as part of a campaign to be paid the voluntary living wage, which is higher than the statutory minimum wage figure. They have also called for Bectu to be recognised and for their concerns about the cinema’s booking system to be heard.

The protracted dispute disrupted the London film festival in October, and strikes are due to be held this weekend. The disciplinary actions are relating to discussions that took place at a private union meeting, details of which were sent out via a union branch email that the company saw and acted upon.

Gerry Morrissey, the leader of Bectu, which is part of Prospect, said: “Bectu members in Picturehouse have been striking for over 10 months for a iving wage, company sick pay and union recognition. It is appalling that Picturehouse and Cineworld would rather intimidate and threaten to dismiss their staff than enter constructive negotiations. This is clearly an attempt to break the union by undermining the strike and intimidating other workers.”

The Picturehouse chain of cinemas is owned by Cineworld, one of the biggest cinema operators in Europe, with 226 cinemas, half of which are in the UK. The 24 Picturehouse cinemas are in cities including Liverpool, Bradford, Oxford and London, and sell an upmarket boutique experience to their clientele, who pay up to £16 for tickets. About 70% of Cineworld’s front-of-house staff in the UK – 3,750, including 700 at Picturehouse – are on zero-hours contracts without sick pay and other benefits such as parental leave.

More than 25 actors and screenwriters including Susan Sarandon and Sir Ian McKellen have urged the public to boycott the Picturehouse chain and Cineworld. They signed a letter, alongside Richard Curtis, Ken Loach, Sir Patrick Stewart and the shadow chancellor, John McDonnell, which was sent to Cineworld’s millionaire chief executive, Moshe “Mooky” Greidinger, demanding better rights and pay for staff.

Last month, Cineworld agreed to meet union representatives to try to resolve the dispute, but union reprentatives say no negotiations have since been held.

Company chair Tony Bloom said at the time that the board was “proud of our employment practices everywhere” and defended the Picturehouse pay rates, claiming they were the highest in the industry, at £9.05 an hour in London (Ritzy staff get £9.10) and £8.18 outside the capital. Including paid half-hour breaks, this amounted to £9.65 – “within inches” of the London voluntary living wage (£9.75), Bloom said – and £8.72 outside London.

Bloom expressed concern about the company becoming a living wage-accredited organisation, like its rival Curzon. “If we agree to the living wage and it rises to £15 next year, we’ll be bound to follow that,” he said.

Picturehouse has also defended its pay structure in a statement on its website: “For many years, Picturehouse Cinemas has paid its front-of-house customer service staff well above minimum wage. Our pay rates are among the highest in the industry and have enabled us to attract and retain staff who are knowledgeable about film, skilled in many areas, and able to offer high levels of service.”

A Picturehouse spokesman said: “This is an internal matter – we are investigating unlawful activities and we cannot comment further at this stage.”

Labour’s John McDonnell, the shadow chancellor, said: “The whole labour movement will stand shoulder to shoulder with victimised workers at the Ritzy cinema and across the Picturehouse chain.

Actions such as these from Picturehouse management are an attack on all of us and they reflect an economy in which it has become normal for workers to be precarious, underpaid and exploited.

“We will outlaw zero hours’ contracts and make sure that everyone is paid a real living wage, and we will ensure that workers have access to justice and that big corporations cannot act with impunity.”