The EPSRC have now mandated open access for their researchers. They have given clear instructions about funding but no time limits or preferred repository. The Policy on Access to Research Outputs page on the EPSRC’s website states:
EPSRC Council agreed at its December 2008 meeting to mandate open access publication, but that academics should be able to choose whether they use the so-called green option (ie, self-archiving in an on-line repository) or to use the gold option (ie, pay-to-publish in an open access journal). Further details will be published in spring 2009.