The addition of Aer Lingus to the website comes during a period of frenetic activity for both Travelsupermarket and the wider travel meta search community in the UK.
Travelsupermarket has spent the most of 2006 involved in a multi-million pound branding campaign on UK television, alongside its sister website Moneysupermarket.
Last week, California-based meta search company Sidestep officially launched its UK & Ireland site and rival US operation Kayak is expected to also make a major offensive on the European market by the end of the year.
Travelsupermarket director Chris Nixon said: “We are very pleased to have signed Aer Lingus to the site.
“This addition will provide users with an even more substantial flight choice at a competitive price.”
Earlier this year Travelsupermarket unveiled its first package holiday search function and has also included user reviews against properties on the site.