PROTECTING Aer Lingus slots at London's Heathrow Airport is "absolutely foremost" in the Government's consideration of any proposed sale of the airline, Tanaiste Joan Burton has said.
The Labour Party leader said the direct flight connections operated by Aer Lingus are "critically important" for investment and tourism in Ireland.
The Government will have to consider a new offer being made by International Airline Group (IAG) which is expected to be made today.
"What we will want to do as a Government, and what is absolutely important, is to protect the slots and the connections of direct flights in and out of Ireland," said Ms Burton.
"The Heathrow flights are of enormous value to Ireland. The key thing is that we keep that connectivity."
Her statement to RTE came as a major trade union warned that IAG could use Aer Lingus' slots in Heathrow for direct flights between the UK and the US, causing international connectivity to Ireland to suffer.
IAG's takeover of Spanish airline Iberia resulted in 4,500 job losses, and an IAG takeover of Aer Lingus could result in 1,200 job losses in Ireland, said Impact union general secretary Martin Staunton.
Executive decisions would transfer to London, with only a token executive presence in Dublin, he warned.
Mr Staunton said the Aer Lingus slots at Heathrow "will make greater returns for IAG if they are used to service the London-US market rather than the London-Dublin market".
"In such circumstances, they would also encroach on the successful direct connections provided by Aer Lingus between Ireland and the US," he said.
"Over one million passengers per year travel from UK provincial airports to use Dublin Terminal 2 as a hub to the US.
"This is lucrative long-haul business that British Airways/IAG would like to reclaim."
An offer by IAG is expected to be made today.
The Aer Lingus board has already rejected two IAG offers of €2.30 and €2.40 per share, but reports suggest a deal is close.
The Government owns 25pc of Aer Lingus.
Transport Minister Paschal Donohoe told RTE's The Week in Politics that "all of our connections are extremely important and the most talked about are the Heathrow slots".