Originally Posted by number_6
EI lounges are rather poor at the best of times. There are only a few routes left that offer J service, and even that is a discounted J (competing on a fare that is roughly half of AA/BA). The J lounges exist at most of the airports which still operate J flights, e.g. DUB, BOS, JFK. The prefered solution at LHR is to use the BA J lounge in T1 which is much nicer than the EI lounge, you can do that if you are OW Sapphire but EI does not pay for lounge access at LHR for anyone based on the ticket. This changed circa April 2005 when EI became a mostly LCC (Ryanair being based in DUB had something to do with it).
number_6 and GoldCircle have indicated that EI makes a distinction between lounges for their elites and lounges for their J passengers. The EI website says:
"Gold Circle Club Members have access to Airport Lounges at most airports served by Aer Lingus. Premier Class passengers will be invited to use these Lounges where available.
To avail of the Gold Circle Lounge you must present a valid Gold Circle Club card along with your boarding card. Premier Class passengers should present your Business Class boarding card."
The website seems to me to say that Premier Class (J) passengers can always get access to any EI lounge.