Union Unite has written to Marks & Spencer to demand urgent talks with the retailer over its ongoing distribution network restructuring.

The union says almost 300 workers are “concerned about their future” at three sites in Belfast, Glasgow and Enfield. This is as a result of the recent opening of two new M&S hubs in Bradford and Castle Donington and plans to open a third at London Gateway.

Two of the three sites affected, in Belfast and Glasgow, are operated by DHL; the Enfield site is run by Wincanton.

Unite national officer Matt Draper said the union had “serious concerns” about the impact of the reorganisation. “There is deep anxiety and uncertainty over jobs and workers are angry that there is no clarity to the proposals being made by M&S,” he said. “If M&S refuses to engage our members are prepared to consider some form of action.”

A spokesman for M&S confirmed the retailer intended to close the Enfield site and reduce operations at the other two locations.

However he declined to comment on potential job losses at the two third party logistics providers, adding: “We understand it will be an unsettling time for all involved and will do all we can to offer support throughout the process”.

Confirming receipt of Unite’s letter, he said M&S would “respond accordingly”.

A spokeswoman for Wincanton said closure of the site, which is scheduled for the first half of next year, would affect 257 employees but that it was “too early to speculate on redundancies”.

Wincanton and M&S would be exploring opportunities for alternative employment elsewhere within the business for affected staff, she added.

DHL had not responded to requests to comment at the time of publication.