The business secretary, Grant Shapps, has written to Twitter to ensure it is complying with UK law after the US company’s new owner, Elon Musk, announced that hundreds of its British staff would be fired. Musk took control of the social media platform at the end of October, and within days launched deep job cuts, with as many as 3,700 redundancies expected worldwide. In the UK, employers are required to launch a collective consultation if they plan to make more than 20 redundancies, as well as consulting individuals. It is thought that hundreds of staff have been locked out of the company systems in Twitter’s British operations, meaning it is very likely to meet the hurdle required for a consultation. Shapps told the Prospect union in a letter on Thursday that he would write to Twitter to “seek reassurance that they will be following all relevant statutory requirements”. “I absolutely agree with you that no company is above the law,” Shapps wrote in response to concerns raised by Prospect, which represents some workers at Twitter. “It must be a very worrying time for the staff and their families,” he wrote. The business department later confirmed that a letter had been sent to Twitter. The social media company is already facing legal action in the US over the speed at which Musk launched the mass firings, locking workers out of company systems before they had been told they would lose their jobs. Unions have raised concerns about its adherence to employment law in Ireland and the UK. Musk, the world’s richest man because of his stake in the electric carmaker Tesla, is attempting to change Twitter’s business model to increase subscriber revenues while also overhauling how it operates, including on Thursday dispensing with the option for all employees to work remotely. He has also forced out much of its previous senior leadership team, including the former chief executive Parag Agrawal. On Thursday, Twitter’s information security chief, Lea Kissner, disclosed that they were also leaving the company. Mike Clancy, the general secretary of Prospect, said he was concerned that Twitter’s situation could be “a digital P&O”. P&O Ferries, owned by Dubai-based DP World, in March sacked 800 workers without consultation, prompting outrage. Another similar situation could prove politically difficult for Shapps, who backed down on a threat of legal action against P&O. The Conservative government has since then acted to limit unions’ power to hold strikes, amid a wave of industrial action. Clancy said: “What we have seen so far from Twitter is a redundancy decision, staff locked out, then the announcement of ‘consultation’. This is an after-the-event attempt to avoid litigation or mitigate compensation, following a decision in the USA that has crashed into UK employment law. “The government must use all its powers to demonstrate no one, least of all big tech, is above the law. It’s time for unions to get stronger powers to stop these abuses and ensure employees cannot just be jettisoned.” Workers at the company are thought to have concerns about whether they were given enough time to appoint representatives, how meaningful consultations can happen when staff are locked out of computer systems, and the process by which the company has chosen whom to make redundant. A spokesperson for the Department for Business said: “We have been keeping a close eye on the situation at Twitter, and we understand that it is a difficult time for everyone involved. While we recognise that tough decisions such as redundancies remain a commercial matter, it’s important that employees are treated fairly and that correct process is followed. The business secretary has written to the managing director of Twitter UK to remind him of his obligations to the UK workforce.” Twitter has been contacted for comment.