Negative UK interest rates were once unthinkable. But tough times lie ahead | Larry Elliott

With the power of ultra-low rates and QE fading, the Bank of England is now considering going negative

• Bank of England: economic shock of Covid-19 less severe than expected

Imagine the scene. It's a year from now and Covid-19 hasn't gone away. The economy is in the doldrums, with unemployment rising and inflation well below its 2% target. The Bank of England has been pumping money into the financial system through its quantitative easing (QE) programme, but to little effect. What's its next move?

One option for Threadneedle Street would be to say it is effectively out of options and pass responsibility for further stimulus over to the chancellor. After more than a decade of ultra-low interest rates and hundreds of billions' of QE, there is a strong case for fiscal policy - tax cuts and public spending increases - doing the heavy lifting.