Following the breakdown of negotiations over a new carriage deal, Discovery is publicly threatening to pull its channels from Sky U.K. in less than a week if the British pay-TV service does not cough up more money.

Discovery alleges that Sky is undervaluing its portfolio of channels. The pay-TV platform, in turn, dismisses Discovery’s demands as “completely unrealistic.”

“We believe Sky is using what we consider to be its dominant market position to further its own commercial interest over those of viewers and independent broadcasters,” Susanna Dinnage, managing director, Discovery Networks U.K. and Ireland, said Wednesday. “The vitality of independent broadcasters like Discovery and plurality in TV is under threat.”

Discovery says it is paid less now by Sky than 10 years ago, despite Discovery’s having increased its share of viewing on Sky by more than 20%. Discovery has also increased investment in original content by more than 30% since 2010, it said, adding new channels to its portfolio, including Eurosport, TLC and Investigation Discovery.

“Somebody has to stand up for consumers, because consumers believe they are paying for choice and diversity — they deserve better,” Dinnage said. “Discovery is prepared to take that stand. Pay-television needs to be about more than just films and football. The consumer can’t be expected to fund all of Sky’s investments and get less and less choice in return.”

She added that Discovery was concerned that if Fox is allowed to take over Sky, as it plans to do, the pay-TV operator’s “market strength and incentive to disadvantage independent TV content providers will only increase.”

Sky was scathing in its response. “Despite our best efforts to reach a sensible agreement, we, like many other platforms and broadcasters across Europe, have found the price expectations for the Discovery portfolio to be completely unrealistic. Discovery’s portfolio of channels includes many which are linear-only, where viewing is falling,” a Sky spokesperson said.

“Sky has a strong track record of understanding the value of the content we acquire on behalf of our customers, and as a result we’ve taken the decision not to renew this contract on the terms offered. We have been overpaying Discovery for years and are not going to anymore. We will now move to redeploy the same amount of money into content we know our customers value.”