On the British Parliament Web site’s listing of members of parliament, most members are given some kind of title preceding their names (“Rt. Hon.,” “Dr.,” “Mr.,” “Ms.”), but some have none at all. I assume there is some objective criteria for titles like “Rt. Hon.” and “Dr.,” but what about “Mr.”? What’s the difference between an M.P. whose name is listed with “Mr.” and one who isn’t?
No difference.
http://www.parliament.uk/directories/hciolists/alms.cfm
All members of the Commons are entitled to use ‘Rt Hon’, should they wish, but not all do. Note also that Tony Blair opts not to use his full first name.
:: Writes I will not assume I know the answer one hundred times ::
The basic gist, that they choose how they wish to be called, stands. From what I can see, there’s only one MP calling himself ‘Rev.’, but I’m sure there’s other clerics in there.
Cool. Thanks.
No problem - so what is it with all these questions recently? We wouldn’t want to be doing anyone’s homework for them 
Okay, I’ll take the hijack. Depressed with American politics. This week’s election in Canada got me looking at other Anglo countries’ politics. Canada led to the United Kingdom. Things are wonderfully complicated there and I can get lost in the minutiae without worrying about real-life policy matters.
Homework! At my age. If only I were so lucky.