The referendum however is "not going to put this issue to bed," Robin Bew, Economist Intelligence Unit's CEO and managing director, told CNBC Monday.
Bew added that while the economic reasons for staying in the EU remained reasonably clear, the voting intentions of the nation are based around a whole series of factors, many of which could be driven by emotive means.
In response to the CBI's latest research, pro-Brexit campaign, Vote Leave, criticized the report on Monday, with its chief executive, Matthew Elliott saying the CBI was "wrong" about its findings.
"The EU funded CBI are desperate to recreate the same scare stories they spread when they urged Britain to scrap the pound and join the euro. They were wrong then and they are wrong now," Elliott said in a statement.
—By CNBC's Alexandra Gibbs, follow her @AlexGibbsy and @CNBCi