British lawmakers have called on the government to curb the "threat" of internet giants to the U.K.'s public service broadcasters (PSBs).

The Guardian newspaper published a letter Friday to Jeremy Wright, the U.K. minister for digital, culture, media and sport, in which a group of nine cross-party politicians warned that if action was not taken "the enormous power of the global internet giants is going to sweep traditional PSB television away."

Public service broadcasting is made of up five core television channels in the U.K., including the BBC, and has been developed over several decades by the country's parliament. BBC television is the only one of the five services funded entirely by British tax-payers.

The signatories of the letter accused internet giants like Netflix and Amazon of "finding ways to circumvent" rules introduced by the 2003 Communications Act, a law that sought to protect British PSBs. They argued that this was being done in various ways, including the building of smart TVs with a Netflix button and burying PSB programs in digital on-demand platforms.

"If we keep allowing them to be pushed out and viewers pushed towards global pay TV services, the PSBs will not be able to (sustained) and we will lose the content that has defined so much of this country for the best part of a century," the letter said. "If the situation is bad now it will only get worse as new TV services are launched by other internet giants. We cannot afford a delay.

"We urge you: recognize the threat and help Ofcom to act to preserve our precious PSBs."