A substantial majority of TEAM Aer Lingus workers are expected to have agreed to the £54.7 million buyout of their letters of guarantee when the acceptance forms are counted on Monday. A "surge" in returns to the facilitator, Mr Gerard Durkan SC, was reported by several industry sources yesterday and more returns are expected on Monday.

Although yesterday was the official deadline for returning the forms, any acceptances that arrive before the envelopes are opened on Monday afternoon will be included in the count.

The growing optimism that a sufficient majority of workers will now accept the buyout package is tempered by concern that "the skills mix may not be right". If enough craft workers do not agree to surrender their letters of guarantee, FLS Aerospace is unlikely to go ahead with its planned acquisition of TEAM. The craft workers are the core asset of the company and a substantial majority which fails to include most of these will not be a viable operational unit as far as FLS is concerned.

In an apparent last-minute effort to prevent TEAM workers from returning acceptance forms, one of the main craft unions, the Amalgamated Engineering and Electrical Union, wrote to the Minister for Public Enterprise, Ms O'Rourke, on Thursday asking for assurances that returning the forms would not undermine employees' statutory rights under the EU Transfer of Undertakings regulations. In response, Ms O'Rourke said that she was satisfied TEAM employees' rights had been fully clarified in the documentation accompanying the acceptance forms. These forms had been cleared by legal advisers for all parties, including AEEU members.

Last May, a first attempt to persuade TEAM workers to surrender their letters of guarantee saw only 41 per cent doing so. The majority of the acceptances were from noncraft employees, with 80 per cent of craft workers holding letters of guarantee failing to respond. They form the core of the remaining 930 employees who have been resisting the buyout package.

The company made a final appeal to employees on Thursday to return the acceptance forms. It said that the consequences for themselves and colleagues of not returning them were "very grim". The senior SIPTU negotiator, Mr Tony Walsh, also urged TEAM workers to return the forms.

The craft unions have largely abstained from commenting, on the basis that members now have enough data to make an informed decision themselves. The co-ordinator of the craft group, Mr Eamon Devoy, has, however, welcomed the "positive" clarifications provided by the chairman of FLS, Mr Steffen Harpoth, when he met union representatives on Tuesday.

The acceptance returns will be counted and verified in the Law Library in Dublin in front of solicitors representing TEAM workers and their unions.

More than 200 TEAM members have threatened legal proceedings against Aer Lingus if they are not accepted back into the group's permanent workforce with full seniority in the event of TEAM's closure.

The company has said that it will take back any TEAM workers with letters of guarantee, but will almost certainly have to make most of them redundant in the near future.