Latest data due out this morning is expected to show inflation is slowing down faster than expected -- but will it be enough to bring down interest rates?

Westpac's Kelly Eckhold says he's picking a headline inflation rate of 3.5 percent.

He says the question isn't whether inflation is going down, but how fast it's going down.

ANZ's Henry Russell and Infometrics' Brad Olsen expect a headline rate of 3.3 percent, but driven by offshore factors.

Russell says a lot of the decline in inflation is being driven by things like food prices, fuel and airfares -- and Olsen says the Reserve Bank will be more worried about "non-tradable" domestic inflation.