A group of TDs have given its support to calls for a separate pension scheme for workers at the Dublin Airport Authority (DAA), as the Government concentrates on the pension issue at Aer Lingus.

The largest union at the authority, Siptu, has warned that its members are being left out of negotiations concerning the pension fund at the airport - a multi-employer scheme serving Aer Lingus, the authority and SR Technics workers.

TDs Noel Ahern, Martin Brady, Jim Glennon, Seán Haughey, Dr Michael Woods and GV Wright have given their support to the DAA workers getting their own pension scheme.

A number of Opposition TDs have also given their support, including Labour's Tommy Broughan and Trevor Sargent, Green Party leader.

In a letter sent to the Minister for Transport Martin Cullen by Dermot O'Loughlin, Siptu branch secretary, the union claims the portion of the pension deficit facing the airport authority is €120-€170 million.

"Whilst not meaning to detract from the importance of any Aer Lingus concerns regarding possible deficits, it should be recorded that the Dublin Airport Authority portion of the pension fund deficit could be recorded at between €120 million and €170 million, depending on which methodologies are used to identify the Dublin Airport Authority's liabilities," the letter stated.

During talks in recent weeks, Aer Lingus management said a €70 million sum, drawn from the proceeds of the airline's initial public offering (IPO), would be used to shore up the Aer Lingus pension deficit.

However, it has not been made clear whether any new DAA scheme would get any fresh funding.

The Government and the airline are desperate to get an agreement on pensions at Aer Lingus by the end of this month. But the DAA workers are unhappy at the lack of political focus on their own problems.

"The Minister has had all the relevant information before him for an inordinate amount of time, yet the Minister has not granted the necessary legislative approval for the scheme," Mr O'Loughlin said in the letter sent to Mr Cullen in recent weeks.

It is understood a meeting took place last week between Mr Cullen and the union, but no concrete proposals have emerged.

Siptu claims it has lobbied the DAA for several months, but has been referred to the Department of Transport.

In a letter sent by Mr O'Loughlin last September to the department, he described the industrial relations climate as poor. He said the environment had been to be good, but this had changed. "Alas all this has changed utterly in the last year or so."