piatkow - 4:43 pm on Mar 3, 2011 (gmt 0)
Ranking will differ according to search engine, enquirer's location and the exact search term.
Supposedly strong backlinks from UK sites will strengthen your position in the .uk versions of the major search engines. Certainly you will get more useful direct traffic from UK links.
I don't know about "regional" as opposed to "national" UK sites.