Thanks for an interesting question.
The most recent (2004) data for per-capita national income, adjusted
for PPP, can be found here:
GNI per capita 2004, Atlas method and PPP
The PPP values for the countries you asked about (using UAE as the
value for Dubai) are as follows:
United Kingdom 31,460
United Arab Emirates 21,000
Normalizing the PPP to a value of UK=100 gives us:
United Kingdom 100.00
United Arab Emirates 66.75
I trust this information fully answers your question.
However, please don't rate this answer until you have everything you
need. If there's anything more I can do for you, just post a Request
for Clarification, and I'm happy to assist you further.
search strategy -- Searched the Worldbank site for [ ppp gni ] based
on my knowledge of this topic.