The report, "The Challenges and Opportunities facing Marketers in 2017", features the results of a YouGov survey of 255 marketers, in which more than half (55%) said the UK’s exit from the European Union was among their top concerns.
Just behind Brexit was recession, cited as a top concern by 47%.
As a result of the UK’s looming constitutional changes, 54% of marketers said they expected to see an increase in "Brand Britain" messaging, and 19% said they were already looking at how to incorporate this into their own marketing.
But the research also suggested that marketers may be complacent about the incoming General Data Protection Regulation, which extends the scope of EU data protection law.
This comes into force in May 2018, when it is likely the UK will still be a member of the EU. Even after the UK leaves the EU, it is likely many of its rules will continue to apply, at least temporarily.
Just 13% ranked the GDPR as a top concern for the year ahead. Only 11% said they already had systems in place to ensure they are in compliance, while three times as many (31%) admitted they did not know whether their business had taken any steps to ensure compliance.
A tiny 6% said they felt they fully understood what the GDPR meant for their business, while 16% believed it was not relevant to them at all.
CIM chief executive Chris Daly said: "While marketers are conscious of many of the challenges that lie ahead and how to address them, they need to be careful that the spectre of Brexit and the plethora of digital trends do not obscure other issues that need addressing.
"It is concerning to see that GDPR has not been fully considered, given the wide-reaching impact this will have on business areas which deal with data – marketers’ natural habitat.
"Given the concerns that emerged from consumers last year over how businesses collect and use customer data, marketers must make sure they are prepared and ready for GDPR sooner rather than later. By staying on the right side of the incoming legislation, marketers are best placed to safeguard not only their business’ reputation, but also its finances."