As such, Bokobza recommended: "Minimal exposure to U.K. assets as political deadlock and delayed tightening by the Bank of England should lead to a weakening of sterling."
This warning comes despite the U.K.'s robust economic growth compared with the euro zone. U.K. gross domestic product (GDP) grew by 0.7 percent in the third quarter on the previous quarter, while the euro zone and France grew by just 0.2 percent and 0.3 percent respectively over the same period.
Read MoreUK economy 'flying'but euro zone a threat: CBI chief
But the French banking group insisted that U.K. assets remained risky, and had continually underperformed.
"We have been underweight on U.K. assets in the last quarters, with little reason for regret. In particular, U.K. equities are underperforming all developed markets, and a lower GBP/USD is one of our strategic calls (with a 1.50 target)," the bank's asset strategy team said.
Read MoreEuro zone GDP beats,Greece emerges from recession
"So far there has been zero structural reform and no improvement in twin deficits or exports despite a significant devaluation of the currency. Also, the spillover effects of weak euro zone fundamentals have been underestimated. We are concerned, and therefore seek to protect our asset allocation."
The recommendations are unlikely to be welcomed by the British establishment. Chancellor George Osborne will deliver his Autumn Statement on Wednesday, updating parliament and the public on the government's taxation and spending plans, which are based on the latest forecasts for the U.K. economy from the Office for Budget Responsibility. With the general election just five months away, this is Osborne's last opportunity to outline his economic plans.