Aer Lingus and Ryanair are battling it out to offer the lowest air fares in their winter sales. Aer Lingus fares start at €9 for its UK provincial routes and €19 for flights to a number of London airports.
European fares start at €39 and a one-way transatlantic flight to Boston will cost €99. Ryanair is offering flights to Europe starting from €19.
Both companies' prices are for one-way journeys only and do not include airport taxes.
The Aer Lingus fares are available until January 15th while the Ryanair sale ends on December 30th.