Reuters ECB sources

Reuters reports that ECB staff at this week's meeting offered a scenario where the central bank would begin a taper in September and finish QE by year-end, then hike rates in mid-2019. Total purchases in Q4 would be 30 billion euros.

The report says the scenario was viewed favourably by ECB policymakers from the north and richer countries while those in the south were more cautious.

"We assumed the market's expectation for tapering and rate hikes in the baseline scenario to look at what sort of financial conditions that would give us," the source told Reuters.

The assumptions largely mirror market expectations.

The report says the ECB hawks won out on the change in language Thursday but the doves are concerned about whether or not inflation was reliably headed to 2%.

Finally, a decision on signaling the end of QE will likely come in June or July, not April.