Bank of England will need to consider Brexit risks

The uncertainty generated ahead of the referendum may not be the perfect recipe for growth. The Bank of England will need to take that into account. For instance, the BoE said in 2012 that the "most extreme" potential outcomes during the Euro-crisis would have had "severe implications" for the UK economy. But it saw "no meaningful way to quantify the size and likelihood" of those outcomes so it did not formally include them in its forecasts. 

The BoE could say similar things this time. It could also choose to delay a rate hike if the referendum vote were due, say, within 3-4 weeks of the interest rate vote. In that scenario, the central bank's information set would improve substantially if it waited a few weeks, whereas the cost of doing so would be low. That calculus shifts away from waiting the further away is the referendum (eg, a plebiscite three months hence may not affect the BoE as much as one due in three weeks).