A proposal by a group of telecommunications companies to build a broadband network would have a fundamental weakness if it was contingent on the involvement of Telstra, the competition watchdog said on Monday. Australian Competition and Consumer Commission (ACCC) chairman Graeme Samuel noted that the G8, as he referred to the group, had already indicated a detailed proposal might be available in the next week or so. "At the present time, there are indications, in terms of public material, (that) suggest that their proposal relies upon some joint venture with Telstra," Mr Samuel told reporters after addressing a Committee for Economic Development of Australia (CEDA) luncheon in Melbourne.