UK’s O2 accused rival EE of “sour grapes”, as the two operators became embroiled in a war of words following the launch of broadcaster Sky’s mobile service.

Sky unveiled its much anticipated mobile offering yesterday, which will use Telefonica-owned O2’s network, and vowed to shake-up the mobile market by offering flexible data tariffs.

However, EE, now owned by BT, which already competes with Sky in the pay-TV, broadband and fixed-line markets, wasted little time in attempting to spoil the party, slamming O2’s network, particularly when it comes to streaming video.

An O2 spokesperson has since dismissed the comments, branding EE  as a “rattled rival”, in a statement emailed to Mobile World Live. 

“We deliver on our customers’ expectations and enhance our network based on their feedback, which is why we have the lowest churn in the industry and the most loyal customers among our competitors,” it added.

O2 went on to cite a recent uSwitch award, giving it the title of Best Network Coverage for 2016, and said it had made a £2 million investment in its network each day over the last quarter.

O2’s retort comes a day after EE went on the offensive.

It claimed Sky Mobile customers will be unable to get the best experience because of O2’s poor network for streaming, citing an Ofcom report, while stating existing O2 customers will also see their service slowdown given the addition of new Sky customers on the network.

The company, UK’s market leader, also provided information from a range of network tests, which, unsurprisingly, showed up EE in a better light than O2.

This included information from tests conducted by OpenSignal, Rootmetrics, P3 and Ofcom.