Two funding agencies, Health Research Board Ireland and Telethon Italy, have adopted open access mandates that require publications resulting from their funded research to be deposited in UK PubMed Central.
Here's an excerpt from the announcement:
Today, this aim takes a step closer as four European research-funding organisations—the Health Research Board Ireland and Science Foundation Ireland, Telethon Italy and the Austrian Science Fund—have agreed to participate in UKPMC. The funders will mandate that all biomedical research outputs that arise from their funding are made freely available—typically within six months of publication—from the UKPMC repository.
(The Austrian Science Fund and Science Foundation Ireland had prior open access mandates.)