Shops should ensure they have carefully thought-out security plans in place for the Black Friday sales later this month, police have warned.
Last year scuffles broke out at a number of stores across the UK as huge crowds grappled for cut-price televisions and other big-ticket items.
Officers will attend shops where necessary, but should be considered as "a last resort" the National Police Chiefs' Council (NPCC) said in a letter to retailers reported by the Telegraph.
Last year's chaos around the event prompted Sir Peter Fahy, Chief Constable of Greater Manchester Police, to condemn lax security arrangements in place to cope with the huge crowds.
Now deputy chief constable Sue Fish, of NPCC's Business and Retail Crime unit, has warned sales should be appropriately staffed and said police are not a substitute for in-store security.
"The police will intervene if necessary to protect public order and safety," she said.
"But we should be the service of last resort, not a substitute for carefully-considered in-store security plans.
"Having to deploy officers to deal with the fallout of highly-marketed but under-staffed sales in shops diverts valuable resources from other areas of policing and is in most cases avoidable through advance planning."
Ms Fish also suggested the event could be extended over a number of days rather than packed into a one-day bonanza.
Asda, owned by American company Walmart and credited with bringing Black Friday to the UK in 2013, announced on Tuesday it will not be part of the sales event this year, which takes place on November 27.
The retailer claimed shopper fatigue had set in around flash sales, and said people prefer deals on products that affect their everyday lives, such as Christmas food and drink and household basics.
Both John Lewis and Tesco have confirmed they will hold Black Friday events this year, with the latter insisting it has put security measures in place to ensure the event runs smoothly.