A strategic shift by the UK's largest mobile operator could leave a nasty taste in the mouths of Carphone Warehouse and its new partner Dixons. The Telegraph reports that just weeks after the two UK retailers confirmed plans to merge in a £3.6 billion deal, EE is deciding whether to end its relationship with Carphone Warehouse, and possibly Phones4U, as it looks to work more closely with customers. EE is expected to make an announcement "within weeks," and could involve dropping either one of its partners, or both. If EE was to sever ties with newly-formed Dixons Carphone, it would lose direct sales from over a thousand high-street stores, which puts more pressure on its own stores to pick up the slack. However, it already counts more than 30 million customers, has a one-third share of the UK market and recently announced plans to boost its retail presence across Britain. Carphone Warehouse has prided itself on being the best place to independently compare deals, but with Three already flying solo and EE set to follow, it could seriously undermine the retailer's claims.