The number of gays follows the global normal distribution.
This Wiki article http://en.wikipedia.org/wiki/Demographics_of_atheism#United_Kingdom
gives the figure as 50% atheist but I have seen figures as low as 35%. However, regular church attendance is also given as ~7%. Of those 7%, most are in the age group +45 years. Elderly women, Catholics and Afro-Caribbeans have a somewhat higher average attendance rate.
These figures are, by nature, vague. In the UK, people over ~45 all received "Religious Education" which was basically "The Bible as understood by the Church of England/Scotland." with a few asides to explain why Catholics do things differently. All this was necessary because the history of the UK from Henry VIII until the late 18th Century was dominated by religion.
From about 1970 onwards, the subject was changed to a study of the systems of general beliefs, in which the basic tenets of the major religions and some minor ones plus ethics was taught. This continues to be the case as far as I am aware.
It is worth noting that the importance of religion started falling dramatically after WW2 with the introduction of free health care, free welfare services, cheap, good quality housing and a revision of the education laws. (There were other factors.)
It is also worth noting that it used to be the case when asked officially for their religion, many people will reply "Church of England" (usually said, "C of E") without thinking. It was also the case that when people replied "None" they were also put down as "C of E" (This is true, as on most official forms there was no space for "None" and the tick box for "Other" did not seem appropriate.)