The UK's competition watchdog, the Office of Fair Trading (OFT), is weighing up whether to carry out a review of the planned merger of mobile phone firms Orange and T-Mobile.
It comes after the pair submitted their proposal to European regulators in a move viewed by many as an attempt to achieve a quicker and more lenient hearing than they might on home turf.
Consumer groups like Which? and Consumer Focus are particularly keen for a UK review of the merger, which will see the new entity overtake rival firms O2 and Vodafone to become the UK's largest mobile phone company. The OFT has until 15 February to make a ruling on the matter.
"It is a significant competition issue with serious implications for UK consumers, the government's Digital Britain agenda and future spectrum auctions," a spokesperson for O2 remarked of the proposed tie-up.
Orange is currently the UK's third-largest mobile operator, while T-Mobile is the fourth. The deal between their parent companies – Deutsche Telekom and France Telecom – was formalised last November, two months after the proposed merger was announced.