David started working for the council in February 1976, a year of heatwaves and a public argument between the council and Derbyshire County Cricket Club which resulted in a season played at grounds across the county.
Celebrating the achievement, Councillor Alan Graves, Council Leader, said:
"As David recounted in his speech, he started working on regional-level plans for economy and infrastructure. With the advent of the Mayoral Combined Authority, these plans are back in fashion again, so we will be dusting off a few of the files that David used to work on!
"David has no plans to retire yet, despite this amazing achievement, so it is fair to say that he truly is '50 not out'!"