Neelie Kroes, commissioner for the Digital Agenda, has said that the European Commission will investigate allegations that telecommunications providers are deliberately blocking or throttling access to voice-over Internet protocol service Skype and similar services.

"One UK operator is said to make Skype calls technically impossible in afternoons and evenings without warning users," Kroes said at a press conference announcing a new report on net neutrality. "Others scare users from using the service or ban it altogether."

"One company operating in several national markets is alleged to severely degrade all VoIP services so that in practice it is very difficult to use them," she remarked.

Kroes said she would need to verify these claims, and will do so before the end of the year. "Mark my words: if measures to enhance competition are not enough to bring internet providers to offer real consumer choice, I am ready to prohibit the blocking of lawful services or applications," she said. "It’s not OK for Skype and other such services to be throttled. That is anti-competitive."

According to Skype, the service is commonly blocked over mobile Internet connections. "Two thirds of UK mobile consumers are prohibited from or over-charged for using voice over the Internet (VoIP) or peer-to-peer applications," it said in a briefing document for a recent panel debate at the House of Commons. "Many are also prohibited from accessing Internet videos, audio or instant messaging other than those provided by their mobile provider."

The company argued that the UK government needs to protect consumers and service providers such as Skype by protecting net neutrality in law. "The way forward for the UK has to be an unambiguous protection of ‘the open Internet’, which will best serve the interests of consumers, as well as the economy and society more widely’."

Speaking at the debate, Kip Meek, senior public policy adviser for Everything Everywhere (the combination of Orange and T-Mobile in the UK) argued that the European Union’s Electronic Communications framework was perfectly adequate to protect net neutrality. "The notion of intrusive regulation seems to be wrong," he said.