The battle lines in the net neutrality war are getting clearer.

On the one side, telephone companies are increasingly united in their insistence that major Web applications and services providers pay for the cost of building the backbone networks required to deliver the growing volume of advanced services. Most recently, Verizon CEO Ivan Seidenberg weighed in on the issue at the BusinessWeek Media Summit in New York Thursday, and according to news reports, dismissed the notion that Verizon would essentially double-charge its broadband customers who are already paying for high-speed Internet access.

“If you buy your DSL [digital subscriber line] from FiOS, you’ll never have any problem with the bandwidth from your house to the first point in the network,” Seidenberg said. “But the issue is that the backbone needs to be built. Who is going to build it?”

ISPs and consumer groups, however, continue to insist that net neutrality is about fairness and open access.

In his remarks, Seidenberg called that kind of thinking “a ruse” and pointed to the need for new commercial agreements that spread backbone costs among the players who stand to benefit, such as Google. He also called for the market to decide the issue, and not regulators or Congress.

Seidenberg is the latest telco executive to speak out on the issue of who should pay for broadband Internet.

The problem, one industry analyst said, is the implicit threat in what telcos are saying.

“The implied threat is that if you are willing to sell someone premium access, or quality of service, then you will allow someone else’s service to degrade,” said Daniel Briere, president of the TeleChoice consultancy. “This comes down to commercial agreements between the ISPs and how they handle peering of traffic.”

Because the issue has become highly charged, however, virtually anything telcos say on the matter becomes instant fodder for Net denizens to go on the attack. Seidenberg sought to frame the issues more clearly in his comments this week, but it remains to be seen whether he has managed to mollify anyone.