Ryanair has added 50,000 extra seats on flights between Belfast International Airport and London Stansted for the winter, while lobbying continues in the Republic of Ireland to lift the cap on passenger numbers at Dublin Airport.

The airport has already reached its annual capacity limit of 32 million passengers, meaning airlines face restrictions on the number of additional flights they can offer during the busy Christmas period.

Ryanair said it normally has up to 270,000 seats available on flights to and from Dublin during the busy Christmas period.

The low-cost airline said it plans to introduce additional flights in the north to compensate for the restrictions.

Ryanair currently flies twice daily between Belfast International Airport and London Stansted.

As of December 20, this number has already been increased to six daily flights.

Ryanair boss Michael O’Leary warned that the inability to offer additional flights at Dublin Airport would lead to a sharp increase in prices.

“Currently, at the end of August, our cheapest fares from London to Dublin on Friday 20th, Saturday 21st or Sunday 22nd December are fast approaching the €100 mark one way because the government has not allowed airlines to offer additional flights to/from Dublin over Christmas.”

The passenger capacity cap at Dublin Airport was introduced in 2007 as a condition of planning permission for Terminal 2.

The reason for this was concern about whether the road network could cope with increased traffic volumes.

Ryanair claims that the number of passengers using public transport has increased significantly since the cap was introduced.

Irish Transport Minister Eamon Ryan is convinced that he cannot legally interfere in an independent planning process.

Dublin Airport has stepped up its lobbying efforts to raise the cap.

In an interview at the weekend, Kenny Jacobs, chief executive of Dublin Airport operator DAA, claimed the cap could cost the Irish tourism industry €500 million next year and put up to 1,000 jobs in the aviation sector at risk.

The operator has submitted a new planning application to increase the capacity to 40 million passengers per year.

Even if the project proves successful, it is expected to take several years to reach the approval phase.

Environmentalists and some residents are against lifting the cap.