The UK should maximise the benefits to the British tax-payer from the research it funds by strongly encouraging not only (as it does now) that all findings should be published, but also that open access to them should be provided, for all potential users, through either of the two available means: (1) publishing them in open-access journals (whenever suitable ones exists) (5%) and (2) publishing the rest (95%) in toll-access journals whilst also self-archiving them publicly on their own university's website.
Scientists do research to create new findings -- to be applied to improving people's lives and to be used by other scientists to create still more new findings. If would-be users of those findings cannot access them, then they cannot be applied or used. Inaccessible research may as well not have been conducted at all.
UK research is funded by the British tax-payer. The researcher is paid to conduct the research and to publish the findings in peer-reviewed journals, but whether would-be users can access those findings depends on whether or not their universities can afford to pay the tolls (subscription, site-license) for access to the journals in which they are published.
No university can afford access to anywhere near all research journals (there are 24,000 in all, publishing 2,500,000 articles per year), and most universities can only afford access to a small and shrinking fraction of them.
A partial solution is to create "open-access" journals that cover their costs by charging the author-institution per article (to peer-review and publish it), instead of charging the user-institutions for access to it. But fewer than 1000 open-access journals exist so far, publishing only about 100,000 (5%) of the 2,500,000 articles published yearly.
The solution for the rest of those articles (95%) is for the authors' own institutions to provide open access to them for all the would-be users whose universities cannot afford the access-tolls of the journals in which they are published -- by "self-archiving" them on their own university websites.
The effect will be to maximise the visibility, impact and usage of UK research and its benefits to the British tax-payer who funds it.
This is followed by the longer (optional) annex at: http://www.ecs.soton.ac.uk/~harnad/Temp/UKSTC.htm