Boon (pictured) has been the face of ICM for many years, leading its polling work. He joined the business straight from university and held board responsibility for all public opinion – covering political polling, social & government research and omnibus services.

His is the second high-profile departure from ICM Unlimited – news of its managing director, Andrew Wiseman’s, departure also emerged in November. 

Boon’s resignation is not thought to relate to the recent changes at Unlimited. The three insight agencies which were part of the Creston Unlimited group – Walnut, Marketing Sciences and ICM – have now merged under the Walnut Unlimited brand. Boon headed up the public sector and social research team; that part of the business retains the ICM Unlimited brand.

In a statement, Walnut Unlimited said: "We can confirm that Martin Boon has decided to leave the business and move on to explore new opportunities outside of the group. Having headed  ICM’s renowned polling services since 2009, Martin has become synonymous with canvassing and predicting public opinion, appearing on almost every major news network to share his insights on the political world, most notably during election times. 

"We would like to thank Martin for his tremendous contribution to ICM and for all he has achieved here. We wish him well for the future. The team he leaves behind remains the gold-standard of public polling made up of exceptional talent, which has cemented ICM’s place firmly at the centre of the national polling conversation. Gregor Jackson, who has been with ICM Unlimited for 10 years, will lead the agency’s public sector and social research team."

Boon said: "After 23 years it’s been a huge wrench to leave a company I’ve loved working for, but the time felt right and the stars aligned for a new opportunity – more of which will emerge in the spring."