People should go into stores rather than rely on online shopping if they want to get Christmas gifts on time, retailers have said, as postal strikes delay parcel deliveries.
« That’s the advice we’re giving, » the boss of bookseller Waterstones said.
Shopping in store will ensure « certainty », the British Independent Retailers Association (Bira) said.
It comes as Royal Mail staff continue strike action, in a row over pay and conditions.
Postal workers are walking out again on Thursday, marking the fourth of six strike days across the festive season.
As a result, letters and parcel deliveries are being delayed.
Many larger retailers have their own distribution networks or deals with courier firms.
But the UK’s largest book chain, Waterstones, is warning customers on its website that the Royal Mail strikes are likely to result in « some delay to our quoted delivery times ».
Its chief executive, James Daunt, told the BBC that buying books in shops is the best option given the strike disruption.
« If people want to be certain of getting deliveries in time for Christmas, they need to go into stores, » Mr Daunt said. « That’s definitely the advice we’re giving. »
Waterstones has more than 300 stores across the UK, leaving it in a very different position to those retailers who don’t have a physical presence, as he acknowledged.
« I know it’s easy for us to say go into shops, as we’re a national retailer, » he said.
« It’s the independent retailers all over the country who will be suffering the most from this. I feel desperately sorry for them.
« For national retailers, it’s more swings and roundabouts. What we lose online, we make in stores. »
Andrew Goodacre, the chair of Bira, said that if customers want to be confident of getting their Christmas gifts on time, their best bet was to go and buy them in person.
« To ensure you get your Christmas gifts on time, we are advising people to go into shops, » Mr Goodacre told the BBC.
« We would always say that anyway as we’d always promote a healthy vibrant High Street, but when there’s so much disruption, not just with postal strikes, but rail strikes too, if customers want certainty on Christmas orders, best to order online, and collect in store. »
But Mr Goodacre warned that it was a difficult situation for small retailers, many of whom will be reliant on Royal Mail to make deliveries.
He said retailers would have been hoping to maximise sales at Christmas time, and the strikes could make that harder.
« They will do their best but it’s a challenge they could do without. »
Meanwhile, the Booksellers Association said the « uncertainty » around parcel delivery dates was likely to push people into shops to get their Christmas gifts.
« This could have the positive consequence of creating more traffic on High Streets and more footfall for bricks-and-mortar retailers, » said Meryl Halls, managing director of the group.
« If the silver lining from the very challenging situation around Royal Mail strikes does help produce busy local High Streets this Christmas, many bookshops will be pleased to welcome the increased traffic. »