By a majority of 77%, members of ALAE agreed in a ballot in August to become a branch of Prospect. ALAE has just over 2,000 members.

Announcing the result of the vote, ALAE chairman Robert Alway said: "This merger is not only great news for ALAE and its members but also for the aircraft engineering community as a whole. The combined strengths of Prospect and ALAE will ensure that air safety remains firmly on the agenda."

The merger will raise Prospect membership to 104,000. ALAE will join Prospect members working in air traffic control and engineering (NATS), British airports (BAA) and regional airports, the Civil Aviation Authority and the Department for Transport.

Welcoming the decision, Mike Clancy, Prospect deputy general secretary, said it was hoped to launch the new branch later in the year.

“This vote gives further momentum to Prospect’s aim of becoming the UK’s leading professional and specialist union.

“We already have many members in aviation and merger with ALAE will further broaden our appeal. We look forward to working with the ALAE executive committee and their representatives to promote the role of engineers and to further their interests.”

ALAE members work for a number of leading airlines, including BMI, Easytech, Flybe, Thomas Cook, British Airways and Virgin Atlantic.

The vote by ALAE follows decisions to merge with Prospect by the Association of Guernsey Civil Servants and the Jersey Civil Servants’ Association. The 19,000 members of Connect, the union for telecoms professionals, will vote on a merger with Prospect in October.