The European Central Bank's chief economist said today that the euro zone faces deflationary pressures, and the bank's president stressed that interest rates must remain low "because the economy is weak".

With euro zone inflation running at 0.7%, well below its target of just under 2%, a raft of ECB speakers this week have said it is open to taking fresh measures to support the economy.

Vice-President Vitor Constancio said earlier this week that "everything is possible".

Both he and Peter Praet have said asset buying - or quantitative easing - is an option after years in which the bank's policymakers have ruled it out.

But the more conservative minority at the bank, who voted against this month's surprise cut in interest rates and are led by its German members, still seem dead set against any such move.

President Mario Draghi yesterday played down the idea of moving deposit rates into negative territory while today he separately stressed the need to keep interest rates low.

"I understand the concerns about a prolonged period of low returns on savings. But it is important to understand that interest rates are low because the economy is weak," Draghi told the European Banking Congress in Frankfurt.

"If we raised rates, we would further depress the economy, people would lose their jobs, and then their savings would be lower for longer."

Praet, who sits on the ECB's six-strong executive board, said the financial crisis had saddled the euro zone with a debt burden unique in Europe's post-war history because it has created a more deflationary environment.

"This is a very different context for the correction of expectations (about income), which is more of a debt overhang," he told a conference at the Bank of France.

"It has more signs of a balance-sheet recession, which is a priori more of a deflationary environment than what we had in the 1960s," added Praet, who is in charge of the ECB's economics portfolio.

Draghi poured cold water on a media report yesterday that the ECB was actively considering taking its deposit rate - now at zero - into negative territory, a move that would see it effectively charge banks to hold their money overnight. 

The OECD threw its weight behind the QE idea this week but, in a telling sign of the fierce resistance such an option would face from ECB hawks, Bundesbank chief Jens Weidmann said printing money is not the way out of the euro zone crisis.

Weidmann regularly stresses the limits of monetary policy and German finance minister Wolfgang Schaeuble weighed in behind him this week.