Ferry operator Stena Line saw leisure travel on Irish Sea routes increase by more than 15 per cent year-on-year last month.

Stena said that based on car volumes in November, the numbers it carried to Britain from the Republic was up 17 per cent. The increase equates to 5,000 additional cars being carried on the firm's Irish Sea routes.

All of Stena's routes have experienced significant increases in traffic, with the largest growth in motor traffic coming on the Dublin to Holyhead route, which was up 19 per cent. Traffic on the Rosslare to Fishguard route was up 12 per cent.

The company said the double-digit growth showed that the ferry industry was continuing its resurgence. Stena Line communications manager Eamonn Hewitt said this reflected the hassle and hidden costs associated with flying, from airport delays to "stealth fees" related to baggage and taxes.

"The continued investment in our fleet of ships, service and facilities is clearly paying dividends and customers are voting with their feet and choosing to travel with Stena Line," said Mr Hewitt.

The firm's main competitor is Irish Continental Group which has been the subject of a protracted takeover battle this year.

The offer period expired last month with neither Aella, a group led by ICG chief executive Eamonn Rothwell, or rival Moonduster, managing to take control.

Property developer Liam Carroll also built a substantial stake in the ferry company.

Stena now has over 30 daily crossings on five routes from Ireland to Britain.

Stena is owned by Sweden's Olsson family who have interests in shipping, property, finance, environmental services and recycling.