The centre left pairing of Labour and the Greens have had a small poll boost in the wake of their decision to announce a formal pre-election agreement.

In the latest One News Colmar Brunton Poll, Labour is up one per cent to 29 per cent, with the Greens up two to 12 per cent.

That takes the centre left Labour/Greens block to 41 per cent.

National however remains in a strong position, although has dipped slightly down two to 48 per cent this Poll.

New Zealand First is steady on nine, as are the Maori Party and Conservatives on one per cent.

Prime Minister John Key. Source: 1 NEWS

Tonight's Poll was taken between the 28th of May and 2nd of June meaning it captured both the Budget and the new Memorandum of Understanding announced between Labour and the Greens last week.

The sample size was over 1500 hundred voters, with 750 voters surveyed before the MOU and 750 after.

When the numbers are converted into seats in Parliament it's a pretty complicated picture.

National would have 58 seats but in a Parliament of 122 would fall just short of being able to form a government, even with the support of its existing support partners ACT, United Future and the Maori Party, who all only get one seat.

It would on these numbers most likely need to rely on New Zealand First, which has 11 seats.

Labour meanwhile would have 35 and with the Greens 15 would muster 50.

But even with New Zealand First on board they would be one short of the 62 seats needed to form a government, creating the possibility of a

hung Parliament.

Meanwhile in the preferred Prime Minister stakes John Key is still holding steady at 39 per cent unchanged this month.

New Zealand First leader Winston Peters. Source: 1 NEWS

New Zealand First leader Winston Peters is the big mover up two points to 12.