Another opinion poll has shown National leading Labour.

The National Business Review poll published today puts National on 39 per cent support, with Labour down to 35 per cent.

A New Zealand Herald poll published on Tuesday gave a very similar result, with National on 40.1 per cent and Labour on 36.2

In both polls, National was ahead of Labour by four points.

Today's NBR poll means National has gained seven points in a month, while Labour has dropped five points.

It recorded another strong showing by New Zealand First, on 10 per cent, and the Green Party also doing well on nearly 9 per cent.

None of the other parties reached the 5 per cent threshold, which they must reach under MMP unless they win an electorate seat.

The two latest polls have shown that National and NZ First could form a coalition government with a comfortable parliamentary majority.

In contrast, Labour would need the help of NZ First and at least one other party.

The trend of falling support for the Government has been apparent for three months, but it accelerated after the May budget and National is now establishing a lead.

The Government has just started fighting back, and is using the parliamentary recess which started this week to spread ministers around the country.

It is also about to launch an advertising campaign under the slogan You're Better Off With Labour.

It will highlight the Government's achievements since 1999, and the improvements in areas like health care, pensions and welfare.