A racial dispute that has rocked London’s legal establishment is centred on allegations of jokes about Auschwitz.

Robert Schon, 52, a senior partner at the City law firm Simmons & Simmons, is pursuing a claim for racial harassment against his employer, alleging that colleagues directed the remarks at him as he left a meeting.

But sources at Simmons & Simmons have dismissed claims of anti-semitism as “absurd” and said it would vigorously fight the action.

The firm, which was founded by the Jewish Simmons twins in the 1890s, has a number of high-profile Jewish clients.

It is thought that an internal investigation of Schon’s claim pointed to an exchange between two of his younger male colleagues.

In this version of events, one of the employees is said to have been discussing a forthcoming stag weekend in Krakow, Poland. When his colleague suggested a trip to Auschwitz, the Nazi concentration camp, the man replied that making such a visit was not his idea of a good time on such a celebratory occasion. It was said to have occurred as Schon was passing.

Simmons & Simmons sources are concerned that Schon’s claim over racial harassment might also be linked to a disappointing annual career review. This centred on his past 12 months’ performance in a year when the firm’s profit per equity partner declined 8.3% to £175,000 — the third successive annual fall.

The company said in April that it would reduce the number of UK partners by 12%.

People familiar with the situation denied that Schon’s allegations were related to any review or Simmons & Simmons’s attempts to encourage older partners to give up “entrenched rights” over their status. This protects them from having their partnerships removed, or dismissal from the company.

Schon, who lives in Hampstead, north London, became a partner at Simmons & Simmons in 1988 and advises international businesses on corporate tax.

Both he and his solicitor refused to comment. Simmons & Simmons also declined to speak.