Stories by Colin James

The Northland by-election did not sharply change national public opinion in the following month, according to the average of the four opinion polls taken in April.

The final election figures for the most part came out close to where the Poll of Polls trend was pointing. National has 47.0%, down from 48.1% on election night.

National got 48.1% on election night figures, while the Poll of Polls trend was pointing to 47.5%, which is where National will end up if it loses 0.6% on special votes as happened in 2011.

National goes into the last week with enough support to govern with just ACT's David Seymore and Peter Dunne of United Future. Its latest average was 47.1%.

National's latest four-poll average was down a bit, to 48.9%, but on this reading the party could still comfortably return to office with its same three support parties.

A new TV3 Reid Research poll published on 10 September kept National firmly in the box seat at 50.3%, fractionally up on its most recent four-poll average reading.

After this week's stream of polls, including TV1's poll published on the evening of September 5, National is back in the box seat with 50.2% on the latest four-poll average.

After two new polls, National's latest four-poll average has risen to 48.9% from 47.5%. Judith Collins' resignation appears to have had no effect on National's standing.

Latest polls put National on a downward trend, but it is a gentle slope. After two news polls, the party's latest four-poll average was 47.5%, down from 48.4%.

Two new polls have affirmed a drop in National's support since July. To govern at the new level it would need, at most, support from ACT and United Future.

Both major parties have slipped in polls taken in the wake the book Dirty Politics. National slid below 50% to 49.1% and Labour is back down to 25.5% after briefly crawling over 26%.

The first poll taken after the Nicky Hager book launch, by DigiPoll for the New Zealand Herald from August 14 to 20, did not dent National's polling average.

Election 2014 - National's polling average was steady up to early August in the poll-of-polls at 50.2% while Labour's average dropped to 26.4%. Two new polls were released on Sunday.

Election 2014 - A new Fairfax Media-Ipsos poll again has Labour at a basement rating of 22.5% and National cruising at 55.1% - but the poll-of-polls scarcely budged.

Election 2014 - Analysis of the latest four opinion polls shows National is vulnerable to a loss if it loses four percentage points from its current support. It is the first column in a special…