Racedo->That is the business of the UK government as the UK government is perfectly entitled to take a stand on ownership that could give dominance over the routes from the UK to one of it's most important trading partners.
Between them Ryanair and Aer Lingus account for about 90% of UK-Dublin flights and the percentage is even higher for Irish regional airports.
The only real surprise is that Irish Authorities haven't shown more interest in the control Ryanair can exert over Aer Lingus.