A body set up to get the UK moving to the net's new addressing system has been shut down in protest at official indifference to its work.
6UK was set up to advise ISPs and firms about the move from version 4 of the addressing scheme to version 6.
But 6UK has been wound up after its board realised its work was futile without official backing.
The indifference means the UK is among the nations that have done the least to move to V6, it said.
"The biggest organisation we needed to join 6UK was the government," said Philip Sheldrake, former director of the non-profit body.
Although the UK government handed over £20,000 ($32,000) to get 6UK going in 2010, said Mr Sheldrake, support had been scant ever since. For instance, he said, nothing had been done to change official procurement rules to mandate the new protocol which would have had a significant effect on adoption.
"There's no material incentive for any organisation to go for IPv6," he said.
The internet grew up using an addressing scheme called IP Version 4 (IPv4).
In the 1970s when the net was being built the 4.3 billion IP addresses allowed by IPv4 were thought to be enough. However, the net's rapid growth has quickly exhausted this pool and led to the creation of IPv6 which has an effectively limitless store of addresses to call on. Europe effectively ran out of IPv4 addresses in September 2012.
Official indifference was revealed, said Mr Sheldrake, by the fact that no government website sat on an IPv6 address.
By contrast, said Mr Sheldrake, countries such as the US had boosted adoption by mandating IPv6 compliance in contracts to force suppliers to work with it. The one factor that made a difference to a nation's adoption of V6 was government involvement, he said.
UK businesses and competitiveness would suffer, he said, as the world moved on with IPv6 but Britain stuck with V4. It was possible to translate between the two protocols, said Mr Sheldrake, but this could disrupt many services, such as Skype, that rely on using the same protocol across the entire net.
Government involvement with IPv6 sat at odds, he said, with its enthusiasm for other digital initiatives such as Tech City.
"If you were going to evangelise Tech City and the UK as a digital hub to the world you probably want to be building that on the modern internet protocol," he said.
A government spokeswoman said the Department for Business Innovation and Skills and the Department of Culture "remain committed to the development of an open internet and regard the use of IPv6 as one of the technologies that is likely to make this possible".
She added: "The expectation was that it would be able to find wider funding and create a central point for the stimulation of IPv6 in the UK.
"We regret that this has not happened. We will continue to explore with industry and other partners the need for IPv6 and relevant ways in which we may be able to assist."