The grand business plan (according to rumour and mutterings in the Irish press) appears to be that EI can do better by routing Irish passengers onto its own long haul routes out of DUB, rather than feeding everything into LHR. The plan is to buy more A330's and expand the network to serve places like BKK and HKG, allowing for connections onto other OW carriers. Naturally enough, BA aren't exactly overjoyed at this prospect.

So, EI propose leaving OW in order to launch the long haul services. Apparently code share relationships with AA, CX, QF remain in place as before.

Now I have to admit that the above plan sounds a tad delusional (they could at least get the services up and running before pulling out) but if they are being outright opposed by BA (and I can understand why BA would not want their feed from DUB cut down drastically) then I can sort of see why they want to leave (or at least threaten to).

The problem for EI< as the above posts make clear, is:

(a) EI needs OW far more than OW needs EI;

(b) If EI does start competing for business on long haul, expect BA to compete relatively vigorously for business passengers.