A BBC proposal to allow other public service broadcasters to make their programming available through its online iPlayer has been blocked by its governing Trust because it was “too complicated” and did not necessarily deliver value to licence payers. The rejection of the “Marquee” project leaves the future of its “Canvas” initiative in further doubt.

Previously known as project Marquee, the open iPlayer plan was to licence the platform to third parties through a new commercial vehicle, establish a federation of public service broadcasters, and create a new web site to which they would all link.

The Trust, while supporting the principle of sharing the iPlayer, said the BBC would need to find simpler ways of achieving this. It said it was not the best way to share the iPlayer or deliver increased public value to licence fee payers.

“We concluded that the open iPlayer plans in their proposed form, combining both commercial and public service elements, were too complicated,” said Diane Coyle of the BBC Trust. “In the meantime, the Trust is open to considering an alternative proposal for the licensing of the iPlayer technology to third parties if that can be done on a simple, fair and commercial basis.”

The Trust reached its conclusion just three weeks after the BBC submitted detailed proposals for the open iPlayer initiative.

Other broadcasters, which have invested in their own platforms, already appeared somewhat sceptical about exactly what was on offer as part of the partnership proposals.

Some observers have suggested that the benefits could have been more easily achieved by simply opening up the iPlayer interfaces and allowing syndication to other services. However, the BBC appears resistant to any erosion of the value of its own branded offering.

The Trust said the “combination of commercial and public service activities was too complex”. It ruled out a standalone plan because of the dependency on public service elements, and said it was not clear whether it was the best way of increasing public value to the benefit of licence fee payers. It concluded that the federation approach was not necessary and suggested that it could raise competition concerns.

The decision follows the ruling by the Competition Commission that effectively killed the Kangaroo joint venture between the BBC, ITV and Channel 4 to operate a video-on-demand platform.

It puts in further doubt the future of project Canvas, another BBC initiative to establish a joint venture platform which also involves ITV. That has raised considerable concerns from some quarters. Sky has submitted that it goes “far beyond the BBC’s remit”.

The Trust is expected to announce its provisional conclusion shortly, but it is now difficult to see how the BBC Trust will be able to approve project Canvas as proposed. If it were to do so, it faces the prospect of further regulatory and legal challenge that could call into question the competence of its governance.

Although it has been criticised for being too close to the executive over which it presides, since it replaced the former board of governors in 2007 the Trust has repeatedly restricted the ambitions of the BBC management in response to industry concerns. While that might be seen as a model of self-scrutiny, it might also suggest a lack of alignment between the governing body and the ambitions of its executive.

The BBC Trust had asked its managers to look at partnerships and technology sharing initiatives, but the responses have so far failed to meet its approval.

The future of the Trust itself is now in some doubt, with politicians of both leading parties questioning the model of self-governance. There is much at stake, going to the heart of the public purpose of the broadcaster, far beyond broadband video services.

To those not imbued with the institutional politics of the BBC and its public service ethos, the decision of the Trust may perhaps seem puzzling, not least to consumers and perhaps those that have proposed such plans. However, it may serve to preserve and protect the long-term survival and independence of the corporation in the increasingly complex environment in which it operates.