A group of former workers at Twitter’s UK operation have accused the company of subjecting them to “unlawful, unfair and completely unacceptable” treatment during a “sham” redundancy process. A law firm representing 43 Twitter staffers who were made redundant has raised the prospect of an employment tribunal to resolve the situation, which it says has been marred by a flawed consultation period under the company’s new owner, Elon Musk. “We consider that an employment tribunal will take an extremely dim view of the company’s failings to date, not least having regard to its size, resources and access to legal advice,” said lawyers at the British firm Winckworth Sherwood in a letter emailed to Twitter executives and seen by the Guardian. The firm said the redundancy process began for the affected employees on 18 November by treating them as if they had already been dismissed, despite a legal obligation to consult with people earmarked for losing their jobs for a minimum of 45 days. It said immediately cutting off employees from internal company systems effectively suspended them from their jobs when Twitter had no contractual right to do so. The letter added that blocking staff from accessing Twitter systems and premises made it “impossible” for employee representatives to help affected colleagues effectively. Winckworth claimed this was a breach of the 1992 Trade Union and Labour Relations Act and that an employment tribunal “would not hesitate to reach the same conclusion”. The letter also claims there was a failure to establish fair selection criteria for redundancy, which it alleges is a further breach of the act. Winckworth said the company’s cost-cutting justification for redundancies, which affected more than 180 people in the UK, was undermined by Twitter flagging “future opportunities” in London on the career section of its corporate website. The law firm said in a “significant number of instances” its clients’ jobs are not genuinely redundant. The letter says that the company claimed the postings might not be “actual adverts”. Twitter made redundant around 50% of its 7,500-strong global workforce soon after it was acquired by Musk in a $44bn (£36bn) deal. Despite this, a substantial number of employees were contacted on 23 December requiring them to respond to invitations about individual consultations on redundancy. Some had been given deadlines to accept settlement terms before their consultations, the letter alleged. “Inevitably, and perhaps intentionally, it caused much stress, anxiety and distress to those affected,” said the letter, which adds that Twitter has used the Acas arbitration service to secure settlements. Elsewhere in the letter, Twitter is accused of failing to respond to formal grievances lodged by individual workers. In the US, the company faces four class action lawsuits, and 200 legal complaints, from affected workers. Twitter has been contacted for comment.