Unions are demanding specific recruitment policies for employment in the new Bellfast base, and Shannon zone business interests opposed to the move are looking at new tactics to sway opinion within the airline, including targeting members of Aer Lingus' employee share ownership scheme (ESOT) which owns 15% of the embattled airline.

Members of the Atlantic Connectivity Alliance have voiced bitter disappointment that local Fianna Fail and government-supporting Independent TDs with links to the Shannon region did not vote for Dail Opposition motions last week calling on the government to use its shareholding to insist on an EGM to discuss the Shannon issue.

A spokesman said the ACA would now be "taking its gloves off in dealing with local TDs after discussions up until now have been diplomatic and polite". Strategy meetings are expected this week to discuss intensifying public pressure on midwest TDs, as well as opening up a new front with Aer Lingus employees.

Already scores of uniformed Aer Lingus staff have marched alongside protestors worried about Aer Lingus's decision to move its Heathrow slot to Belfast, but the new approach is understood to be based on presenting a detailed commercial analysis of the effects of moving to Belfast to the ESOP.

This analysis is expected to show that the decision to fly from Aldegrove is a commercially-flawed plan which will affect Aer Lingus' bottom line and hence the value of employee's investment in the company.

Meanwhile, Aer Lingus senior management were dealt a broadside by unions last week when they demanded that any recruitment for staff at the new Belfast hub must be recruited through Dublin and avail of collective agreements negotiated by IMPACT and the Irish Association of Airline Pilots.

Dermot Mannion has written to the unions pointing out that IALPA's demand to recruitment through Dublin would deny equal job opportunities to local candidates in the north.

IALP has reportedly not responded to Mannion's assertions as most of its executive was in the air.