FRANKFURT (Reuters) - Any move by the European Central Bank to buy government bonds would be "very borderline" and should not be made hastily, ECB Governing Council member Ardo Hansson told a German newspaper.
"Governments could borrow more money than before because the interest costs would be lower," Sueddeutsche Zeitung quoted Hansson as saying in a summary of an interview to be published on Saturday.
One would then have to ask "whether the ECB is illegally financing states or not," said Hansson, who is the head of Estonia's central bank.
Having largely exhausted its policy tool-kit with its main interest rate at a record-low 0.05 percent, broad-based buying of sovereign bonds - known as quantitative easing (QE) - is seen as the ECB's last resort to prevent a slide into deflation.
ECB President Mario Draghi said after the 24-member Council's December meeting that it would reassess policy early next year and alter the "size, pace and composition" of the ECB's measures if needed.
"We all know that there are political parties in the euro zone that promise to refinance their government debt once they are in power," Hansson said.
Asked whether the ECB should still buy government debt, despite knowing the risks, Hanson said: "This demand is very borderline."
He warned against a hasty decision on the matter, saying: "The geopolitical situation and the slide in oil prices have caused much uncertainty. That makes it more difficult to interpret the situation in the medium term."
The ECB's Governing Council holds a monetary policy meeting on Jan. 22.
(Reporting by Maria Sheahan; Editing by Dominic Evans)