“It is an enormous privilege to be general secretary of Prospect,” said Clancy, whose current term as head of the professionals’ union ends next March.

“Despite the considerable challenges unions face, the vital role Prospect plays in protecting workers rights and giving workers a voice has never been clearer to me.

“Together, staff and representatives are building a new union and with the arrival of our colleagues in BECTU, I aim for us to deliver the best possible service to our 140,000 members.

“Our recent programme of recruitment events in Union Week showed that Prospect’s politically-independent evidence based-approach, as well as its diverse knowledge of industries across the public and private sectors, is very attractive to potential members.”

Clancy has been a full-time union officer since 1989, first with the Engineers’ and Managers’ Association and then with Prospect following the merger of EMA with the IPMS union in 2001. He is a member of the TUC general council as well as serving on the council of conciliation service ACAS.

Prospect president Denise McGuire added: “It's inspiring to have unity across the union in our choice of general secretary. We congratulate Mike and give him our best wishes for the future as we work together to deliver a great union for all our members.”