The best way is to write to the PhD offices at those universities where you are apllying and ask them what they can offers. Or you can visit univesities' websites and look at "funding for postgraduate students".
You might want to think about applying for funding from the ESRC - their website is http://www.esrcsocietytoday.ac.uk/ESRCInfoCentre/opportunities/postgraduate/. You will need to come up with a research proposal and find a supervisor and institute first. It's fine to contact academics working in the area you would like to research in directly, to see if they are interested in supervising you.
A few people I know who didnt get ESRC funding but had applied (after finding a supervisor and university willing to take them) were then funded by their departments anyway - dont know if they were just very lucky!
ESRC - very competitive but the best place - make links with a talk to a supervisor before putting in a proposal - work on that bid as it needs to fit in with the esrc profile and the expertise of your proposed supervisor