Marks and Spencer is set to witness a protest outside its London HQ tomorrow (28 October) by workers sacked from poultry supplier 2 Sisters Food Group.

The planned demonstration is the latest twist in a racism row that has engulfed 2 Sisters, an own-label supplier to UK retailers.

Claims of racism at the company first emerged last month after alleged racial abuse at a 2 Sisters site in Smethwick, Birmingham.

2 Sisters suspended employees who took unofficial action to back the plant's shop steward, who had earlier been suspended for supporting the victim of the alleged abuse.

The Unite union now claims 2 Sisters "sacked" 59 members of staff for "standing up to racism in the workplace" and plan to deliver a letter to M&S executive chairman Sir Stuart Rose in a bid to get him to intervene.

"They are calling on Sir Stuart Rose to intervene and urge 2 Sisters, a major supplier to M&S, to re-instate the sacked workers," Unite deputy general secretary Jack Dromey said.

"If you have the power to stand up to racism, then it is your duty to act. In good faith, we sought to build a better relationship with 2 Sisters, working with M&S.

"But 2 Sisters has repeatedly broken promises to improve. Now we have 59 workers sacked, triggered off by racist abuse. I am disappointed that M&S has gone backwards, but it cannot escape its responsibilities now to move things forward."

2 Sisters, however, insists that the dispute is nothing to do with M&S, which does not buy from the plant in Smethwick.

"Unite's planned demonstrate outside Marks & Spencer, a company that has nothing to do with this site, is disgraceful," 2 Sisters chief executive Ranjit Singh said.

"The employees were dismissed for their part in an unofficial strike that no business should be expected to tolerate."

Singh added: "This isn't about racism or the actions of corporate businesses, this is a PR stunt by Unite to try and demonstrate its strength to its members. This is typical of Unite's bullying tactics, which is completely out of touch with the current economic climate."