All 31 economists surveyed say the bank's rate-setting committee known as 'Copom' will reduce the Selic rate by half a percentage point for the third successive meeting. A dovish outlook for the next year from 25 economists was also unanimous.
In a September poll on the skew for rates over the next year, 22 analysts said it was downward, three said it was neutral, and two said it was higher.
Copom is expected to announce its decision after 6 p.m. (2100 GMT) on Wednesday, at the conclusion of a two-day meeting.
The overall economic picture is little changed from the last meeting: lackluster domestic growth, inflation below target and falling, U.S.-China trade tensions, weaker economic growth overseas, and widespread global monetary policy easing.
What tilted an overwhelming expectation of lower rates six weeks ago to a unanimous view now has been clear signals from central bank officials, including President Roberto Campos Neto, that low inflation has opened the door for bold action.
In addition, the exchange rate has broadly held steady since the last interest rate cut in September. Indeed the real rose this week to its strongest in two months, as the dollar fell below 4.00 reais for the first time since mid-August.
Congress has also helped the case for more stimulus by passing a sweeping social security overhaul, cutting pension costs to stabilize public finances. Campos Neto has said ongoing economic reforms were key to allowing further rate cuts.
"The stars are aligned," said Tony Volpon, chief economist for Brazil at UBS in Sao Paulo. "The real could weaken, but not enough to stop the rate-cutting cycle."
Since Copom last met, inflation in the 12 months through September fell to 2.89%, further below the central bank's 2019 target of 4.25%. In the month to mid-October, consumer prices edged up just 0.09%, the smallest monthly rise in October since 1998.
The central bank's official 2020 inflation target is 4.00%. According to its weekly survey of financial institutions, economists see inflation around 3.66% next year.
Roberto Secemski, Brazil economist at Barclays, last week revised down his end-2019 Selic forecast to 4.50% from 4.75%. He expects the increasingly benign inflation outlook to trigger rate cuts of 50 basis points this month and December, in line with the weekly central bank survey.
As long as economic growth remains subdued and the exchange rate does not weaken dramatically, further interest rate cuts are likely to remain on the table, economists say.
The government, central bank, and private-sector economists expect growth this year to be under 1.0%, below the 1.1% pace in each of the previous two years and confirmation that the economy has failed to recover meaningfully from the 2015-16 recession.
(Reporting by Jamie McGeever; Additional reporting by Gabriel Burin in Buenos Aires; Editing by Brad Haynes and David Gregorio)
By Jamie McGeever
