Ironside, a former managing director of the Mail on Sunday and an independent media consultant, joined NRS in January 2009, replacing Roger Pratt.

Simon Marquis, chairman of NRS, said: “Mike has achieved everything and more that I could have wanted when we appointed him five years ago. He has given the NRS a complete makeover and I think the market sees it in a very different and positive light as a result. I’d like to thank him for his energy and commitment to the NRS and also for giving us such advance notice of his future plans. It gives us plenty of time to find his successor.”

One notable development during Ironside’s time in charge was the launch of a fused print and digital readership study, called PADD.

Ironside said: “I have had a thoroughly absorbing time at the NRS, leading a major change programme and I hope people will judge that the survey is in a far better place now than when I took over in 2009. I am confident that the team I leave behind will continue to drive the NRS forward and I would like to thank them all for their support, professionalism and sheer bloody mindedness in bringing the survey into the world of multi-platform.”