Inflation in the eurozone may exceed the European Central Bank's forecast in the long run, so there is no reason to expand a legacy bond purchase program when an emergency scheme expires next March, according to ECB policymaker Madis Muller.

The European Central Bank is debating what happens after the 1.85 trillion euro ($2.08 trillion) Pandemic Emergency Purchase Programme expires.

A bleak economic outlook has divided its 25-member Governing Council on what course to take at a crucial policy meeting on December 16 – decisions that could determine its actions for the rest of 2022 and possibly beyond.

Conservative policymakers argue that inflation, which is currently running at more than twice the ECB's target of 2%, may remain too high even in the long run, while doves warn that price pressures are still too weak and that abandoning ultra-easy monetary policy now risks undoing years of stimulus.

ECB's Muller says central bank could do "even more unconventional things"  in slump

"The Pandemic Emergency Purchase Programme (PEPP) can go to zero in terms of net purchases by March 31," said Muller, Estonia's central bank governor adding, "Beyond that, it's not obvious to me that we should – in addition to what we have already communicated in terms of continuing purchases under APP – commit to adding further stimulus on top of what we have already."

Bond purchases under the Asset Purchase Programme (APP) are currently at 20 billion euros per month, with market analysts expecting this to more than double in April, replacing much of the lost stimulus from PEPP, which has kept the bloc afloat but is now seen as having completed its mission.

Muller argued that because uncertainty about both growth and inflation is unusually high, the ECB should keep its options open in order to change course quickly if necessary. "Given the uncertainty surrounding the near-term outlook, I think it would be wise not to commit to a specific level of purchases for more than a few quarters ahead," he added.

The ECB should also refrain from announcing an end date for its bond purchases in order to keep its options open.