The latest Roy Morgan poll has National extending its lead by 5.5%, up from the 13% lead in December.
What is interesting about this is that normally January is the best month for incumbent Governments. People are on a break, it is summer, everyone is relaxed and there is little coverage of politics, and no opportunity for opposition parties to get publicity through the House.
January 2007 saw the public poll average have Labour go from 7% behind in December to 1.5% ahead.
January 2006 saw the public poll average have Labour go from 2.3% behind in December to 6.0% ahead.
Also if we go back to January 1999, the final summer before that election, National was 17% behind in the Nov 99 TV3 poll, and the next poll had the gap close to just 6%. The TVNZ poll had Labour 10% ahead in Dec 1999, and this shrunk to 1% in their next poll.
So while not a hard and fast rule, it is unusual for an incumbent Government not to improve over summer, let alone for it to fall a further 5.5% behind.