Vodafone and O2 have reacted furiously to the news that Ofcom has granted Everything Everywhere the right to use its existing spectrum for 4G services.
The decision was granted on Tuesday, after several months of deliberation from the media regulator and much lobbying by Everything Everywhere, and means that from 11 September the firm can begin using its 1800MHz holdings for 4G.
This has prompted an outraged response from Vodafone, which said it was "shocked" by the decision and criticised the regulator for undoing all of its own work in trying to create a level playing field for the 4G auctions, which are set to take place in 2013.
"The regulator has shown a careless disregard for the best interests of consumers, businesses and the wider economy through its refusal to properly regard the competitive distortion created by allowing one operator to run services before the ground has been laid for a fully competitive 4G market," it said.
"The regulator has spent several years refusing to carry out a fair and open auction. Now its decision today has granted the two most vociferous complainants during that entire process a massive incentive to further delay it."
Meanwhile, O2 has also expressed frustration with the decision, citing similar concerns.
"We are hugely disappointed with today's announcement, which will mean the majority of consumers will be excluded from the first wave of digital services," it said.
"This decision undermines the competitive environment for 4G in the UK."
O2 and Vodafone have already announced a partnership around the rollout of 4G infrastructure to combat the advantage they believe Everything Everywhere has in the race to bring out 4G services.
Facebook and CVs. What could possibly go wrong?
OnePlus volte face will also enable users to opt-out of company's device data collection practice
Dorsey promises "more aggressive stance" on rules and enforcement
A team of US researchers have confirmed that an exploit can hack into any WPA-2 wireless network, but details are slim