The Science Museum has been accused of “staggering” hypocrisy after writing to the police about its striking staff members who want to stand up to the far right.

On Saturday, former EDL leader Stephen Yaxley-Lennon (AKA Tommy Robinson) will hold a demonstration in London – his first since returning to the UK after fleeing a court case. In July, Robinson gathered 15,000 followers to demonstrate in central London just days before far-right riots broke out across the country. He will be opposed by a large anti-fascist demonstration.

The same day, outsourced security workers at the Science and Natural History Museums are set to strike over stagnating pay. The United Voices of the World (UVW) trade union is organising a mass picket outside the world-famous Science Museum, and plans to join up with the anti-fascist mobilisation afterwards.

In an email seen by Novara Media, Sarita Godber, the Science Museum’s director of people and culture, praised the anti-fascist mobilisation against Robinson, saying it is “representative of the unity shown by communities across the country against the disgusting far-right riots earlier this summer”.

However, Godber writes: “Regrettably the UVW has posted some information on social media that links these two separate issues – the national anti-fascist demo and a pay dispute, talking about ‘two meet up points, one march’ with the aim of bringing protesters together to unite against ‘bosses and the far right’, with one of the meeting points named as the Science Museum.”

The museum is concerned for “the safety and wellbeing of our colleagues and visitors coming to the museum that day”, she wrote.

“With the support of the [trade unions] FDA and Prospect, we have written to the police to express our concern over the mass picket given the potential safety considerations.”

Prospect, which represents in-house workers at the museum, also sent a remarkably similar email to its members, discouraging them from joining the picket.

Petros Elia, general secretary for UVW, said: “The hypocrisy of the Science Museum in this case is staggering.

“Nimbyism comes to mind here: ‘anti-fascists are great just as long as they’re not in my backyard’.”

The Science Museum’s claim to have the support of trade unions FDA and Prospect in writing to the police drew sharp criticism from Elia. He raised concerns about a risk to his members’ rights to freedom of assembly and association. In 2022, the Met released a grovelling apology and paid thousands of pounds in compensation to UVW’s former legal head Frank Magennis after it arrested and handcuffed him on a picket line at a south London hospital.

He said: “Needless to say that none of these unions or the museums or the security contractor Wilson James have spoken to UVW or any of the security guards in relation to their purported and completely unfounded concerns.

“Both unions and museum management are all claiming that by attending the picket line there is a potential risk to the safety and well-being of museum visitors and workers because some of the people who support the picket line are anti-fascists. This appears to be creating a hierarchy of ‘acceptable’ trade unionists and trade unionism.

“The reason some anti-fascists will be joining the picket line is to stand in solidarity with the security guards, the majority of whom are migrant workers. Nothing more, nothing less. It’s as simple as that. After all, they are also workers and trade unionists! For management to misconstrue this obvious fact is unsurprising, but for unions to do so is bewildering.”

A Science Museum spokesperson said: “We, together with the Natural History Museum and two of our recognised unions, FDA and Prospect, are concerned about the implications of UVW’s approach, particularly for the safety and wellbeing of our colleagues and visitors during the busy half term holiday.”

Sue Ferns, senior deputy general secretary of prospect, said: “Prospect supports the UVW members in their strike action, has circulated details of their strike fund, has encouraged members to support demonstrations by striking members of the UVW on other dates, and has instructed members not to carry out work that would normally be carried out by members of the UVW.

“As you will be aware Science Museum Group and the Natural History Museum are not the employer with whom UVW has a dispute – that is Wilson James. Therefore, Prospect members employed by the museums cannot legally join the strike action.

“The safety of our members will always be our most important priority. Given the likely conflation of issues around the demonstration on Saturday and the fact that our members will be working at the museums on this day, we have raised our concerns about members’ safety with the employers concerned.”

Wilson James and the FDA have been approached for comment.