A leading consumer organisation has backed the decision of the Office of Fair Trading (OFT) to investigate the proposed merger between broadband providers Orange and T-Mobile.
Peter Vicary-Smith, Chief Executive at lobby group Which?, said there is "no reason" why the European Commission should object to this move.
He claimed that it is "only right" that a deal affecting UK consumers should be scrutinised by domestic regulators.
Mr Vicary-Smith commented: "This merger will clearly have a huge impact on the mobile market, since it will form the biggest mobile operator in the UK and bring the number of networks down to just four.
"We don't believe the deal should go ahead unless the OFT and Competition Commission are satisfied there will be no detriment to UK consumers."
Meanwhile, Philip Cullum, Deputy Chief Executive at Consumer Focus, also welcomed the OFT's decision to seek a referral on the deal.
He said the organisation was concerned about any reduction in competition and choice in the mobile broadband market.