Holder, who died on 14 February, developed the world's first professional direct marketing qualification in 1981 before co-founding the IDM in 1987 with the mission to help marketers develop their careers.

BEC London creative partner Chris Barraclough said: "Derek Holder did more than educate a generation of marketers in direct and digital marketing: he was a major part of a movement that professionalised our industry.

"As head of the IDM, he inspired a generation of clients and agency principals to rigorously analyse what they did. The IDM is his epitaph. But I also remember a lovely, kind man who was always ready for a good lunch and hours of fascinating debate, chat and gossip."

In the 25 years that he led the organisation, it educated and inspired more than 50,000 marketers and developed professional qualifications across a wide range of fields, including direct, data, digital and integrated marketing communications.

DMA chief executive Chris Combemale said: "Derek was an inspirational leader of the direct marketing industry. He realised many years ago that the industry needed professional skills and talented people to achieve its potential.

"He founded the IDM with a passionate commitment to academic rigour and professional excellence. In today's world of modern marketing, every marketer and every company have become practitioners of the skills Derek cared so much about.

"Derek educated generations of direct marketers. Many of our members feel indebted both professionally and personally to Derek for the skills they learned from him. He will be sorely missed by all."

The Direct Agency chief executive Heather Westgate added: "If I had to choose one word to describe Derek, it would be ‘tireless’. Nothing ever got in his way as he proceeded on his mission to enhance and improve the direct marketing industry through education.

"Each of us owes an immense debt of gratitude to Derek. His attitude and foresight played a significant role in developing the industry and making it the vibrant, dynamic profession it is today."

A private funeral well be held tomorrow (28 February) and the family has requested that, instead of flowers, donations be made to the family's chosen charity, Macmillan.

A dedicated Facebook page has been set up for friends and colleagues to share their thoughts and memories, while plans are also underway for a celebration of Derek's life to take place this summer. Details will be available from the IDM nearer to the time.

A spokeswoman for the IDM said: "Derek was immensely proud of what the institute achieved, but never once took the credit himself, ever-quick to acknowledge the efforts of those who worked both for and alongside him. The IDM Trustees and Directors will continue to uphold his principles and pursue his mission for many years to come."