I did some research and this is what Wikipedia threw up:
Irish Breakfast tea is a full-bodied, malty brew. It is a blend of several black teas; most often Assam teas and, less often, other types of black tea.
Some of the brands of Irish Breakfast tea include Barry's, Bewley's, Republic of Tea, Twinings, Taylors of Harrogate, Stash Tea Company, Fortnum and Mason, Mark T. Wendell, Harney & Sons, and Upton Tea Imports. All of these and many other companies create their own blends of Irish Breakfast tea.
In Ireland, it is not referred to as "Irish Breakfast tea", but simply as "tea". It is enjoyed throughout the day and evening.Interesting. So, while Earl Grey and English Breakfast Teas are established, recognised blends which are protected under the Trades Description Act (meaning Earl Grey is Earl Grey regardless of where in the world it is blended or bought because its always exactly the same blend of tea), "Irish Breakfast" is a nominal name for any blend which you might care to chuck together. Different brands of Irish Tea will taste different because each company basically make up their own recipe.
The last sentence is revealing. Even the Irish don't refer to it as "Irish Breakfast Tea" - and they drink it all day. So it has nothing specifically to do with breakfast. Or indeed the Irish. Unless its in a Kelly Green box with a shamrock on it, of course.
This is a job for the guys over at Honest Labelling.
Chelsea Foods' "response" consisted merely of cutting and pasting the Wikipedia entry quoted above into an email, ending with the incrediby rude final line "As for your comments regarding the affordability of the people [sic] living in the Croft House on the front of the box, can I ask how you would know?" Simple, Mr. Keith Mead from Chelsea Foods. Tea and its relative price over the centuries just happens to be something about which I know quite a lot. So, Rule #1 of responding to requests for information - don't assume that your customer is ignorant of the facts.