Should BT be forced to separate from Openreach?

But Vodafone UK's chief executive, Jeroen Hoencamp, told the FT that the industry is paying the price for "inappropriate" expenses.

He said it was "unacceptable that BT loads its Openreach unit with inappropriate costs from other parts of its business, which it expects to be paid for by the rest of the industry and passed on to customers".

But while Vodafone has essentially accused Openreach of putting BT before its other customers, BT ponts out that none of its rivals have ever put forward a formal complaint to this effect to Ofcom. So if Vodafone is so sure, why hasn't it ever mentioned this to the regulator?

"There is already regulation in place which prevents us from doing that, with very heavy penalties if we did; Ofcom have the ability to fine you up to 10 per cent of revenues... moreover those people haven't raised an official complaint which [suggests] that this isn't happening," said Shurmer.

But BT's rivals still smell a rat. When Openreach's previous CEO, Joe Garner, suggested that a full separation would be bad for Britain, Sky's Fyfield argued that the fact Garner was commenting so forcefully for Openreach to remain a part of BT, when Openreach is intended to serve the market equally, shows that the existing system is broken.

Vodafone's Braovac said there's a telling contradiction in BT's arguments:

"They [BT] claim on the one hand there is no benefit from owning Openreach; they say they are treated like any other customer thanks to the [existing] rules, yet at the same time they argue very strongly that they couldn't possibly spin Openreach off and I think it is difficult to understand that if the first bit is true, then why is it that the second is such a big problem for them?"

When Computing put this to BT's Shurmer, he said:

"We think it's bad for BT and its shareholders and bad for the UK, we say that because it's principally for investment; the UK gets more investment by having Openreach as a part of BT Group."

But Braovac suggested that BT shareholders would benefit from a split.

"Current shareholders would receive a new BT retail share and a share of Openreach - so of course, some investors would want to be in the quite exciting, downstream, TV and mobile business which BT is, and others would be looking for a long-term stable return on their capital like infrastructure funds and pension funds," he said.

TechMarketView founder Richard Holway agrees with Braovac.

"Contrary to what BT has tried to persuade people into thinking, I think a separate organisation would be good for BT shareholders and for the industry as a whole," he said.

A separation, according to Sky, would also enable Openreach to look at potential new infrastructure projects and other areas of investment.

"The idea of Openreach seeking outside investment is unthinkable while it remains part of BT," said Fyfield.

"Although Sky is Openreach's biggest external customer, they have never brought us a proposal to invest in an infrastructure project," she added.

It would also mean that other companies, such as Vodafone, could take a stake in Openreach - something the firm has openly stated it would like to do.