The Deputy Prime Minister says Labour wasn't expecting to see a "Covid bump" in the polls.
The latest One News Colmar Brunton poll has the party sitting on 43% down 3% since May.
National's also fallen 3% to put it on 26%.
Grant Robertson says that's a reflection of the challenging times.
He says no one wants to be in a lockdown but they're overall happy with the solid support.
David Seymour saw another rise, with Act and his personal rating lifting 5%, to put the party on 14% and him on 11%.