Bank of England governor Mark Carney refused to speculate on the economic impact of a referendum on EU membership or disclose any information regarding the Bank's contingency plans.
"It serves no-one at all to talk at length about the specifics of those contingency plans in advance," he told journalists after the monetary policy committee decided to keep interest rates at record lows.
He added that in the Bank's forecasts published today "we assume the status quo".
Carney said business investment had grown at above-average rates in recent years.
Asked how a referendum might affect , Carney said: "We will have to see. It will be a product of how the campaign unfolds."
The Bank cut its business investment projection for this year to 5.5 per cent from 7.5 per cent in November's forecasts. It then expects investment growth of six and 6.25 per cent.
Carney announced after the Scottish independence referendum in 2014 that the Bank of England had contingency plans for how to operate the currency and banking system if Scotland had opted to leave.