Claims by Labour and unions about superannuation entitlements under National are about as credible as a Helen Clark painting, National's finance spokesman David Carter says.

Carter says both National and Labour are committed to the current superannuation scheme, which guarantees retirement income of 65% of the net average wage at age 65.

"However, where we do disagree with Labour is about how to provide a secure long-term future for New Zealand's changing demographics.

"Labour is locking New Zealanders into higher taxes for at least the next 30 years to provide the $2 billion a year to the Cullen fund. It is then going to export the vast majority of this money overseas - to the benefit of other countries and not New Zealanders.

"Meanwhile, the Cullen fund - according to the Government's own figures - will only provide about 10% of New Zealand's superannuation requirements in 30 years time.

"National believes the best way to tackle New Zealand's ageing population is to set the country on a path of long-term, sustainable growth rates. Our economic framework is about locking in high growth rates that will provide a better future for all New Zealanders.

Carter says voters at this year's election have two clear options.

"New Zealander's have a stark choice between Labour's high taxes, low ambitions and politics of envy, or National's aim of creating a world-class economy that allows for world-class health and education as well as rewarding success," Carter concluded.