Labour could still win power at the next election, National deputy leader and Finance Minister Bill English said in a speech warning against complacency.
"The Opposition can be divided, it can have many leaders and co-leaders, it can have no vision, very little policy, be disorganised but under MMP it can win and we need to remember that every single day.''
Mr English was speaking at National's northern regional conference in Auckland this morning.
He said National would need to win the highest vote any incumbent Government had ever won - it was re-elected for a second term in 2011 with 47.31 per cent of the vote.
He also told delegates to make no assumptions about who was a potential voter, pointing to a large representation at the conference from south Auckland.
Political polls consistently have National well ahead of Labour but not always in a position to govern.
The March Herald DigiPoll survey had National on 50.8 per cent and able to govern alone compared with Labour's 29.5 per cent and the Greens 13.1 per cent, a combined 42.6 per cent, but the polling of New Zealand First and smaller parties such as the Maori Party by just a percentage point or two can dramatically alter the results.
See the results from the most recent Herald Digi-poll survey here:
Mr English said despite the Government's achievements in addressing a broad range of issues from the crime rate to reducing welfare dependency and the improvement in the economy, voters would not be thinking about rewarding National.
They would be thinking about which party could support them best and offer them the best opportunities.
He praised Prime Minister John Key whom he said engaged "respectfully, warmly and openly'' with a broad range of New Zealanders everyday through the media and in person.
To a question from the audience, Mr English defended National's decision to keep the pension age at 65, as per a promise by Mr Key in 2008.
If he now raised the age "frankly no one would believe anything else he ever says''.
"John Key means what he says and that has been a critical part of the trust the public has had in this Government.
"Quite apart from the super issue, that is critical to our broader credibility, that we have got a Prime Minister who deals with them honestly and sticks to what he says.''
Sticking to the promise had allowed the Government to focus on other costs.
After 30 years of debate about retirement policy, it was now settled because of the firm undertaking not to change national superannuation.
"And for the time being we can afford it. In this Budget [on May 15] we will run a surplus, we will pay national super to about 600,000 people.''
The cost of super was going up every year by about $300 million to $400 million and that would pick up a bit. "We are paying the bill.''
Mr English slammed Labour's new monetary policy tool which would allow the Reserve Bank to adjust up or down the KiwiSaver rate for employees' contribution within a band of about 8 to 10 per cent.
Mr English said people preferred simple rules they could understand and everyone knew what happened when interest rates went up.
KiwiSaver was a completely different thing.
"KiwiSaver is long-term retirement policy that is designed for stability over 30 to 50 years.
"You do not want the Minister of Finance messing around with that every six weeks like the Reserve Bank does with interest rates.''