New Zealand First leader Winston Peters has lashed out at the National Party in a speech signalling his party's direction for the election.

But he's stopped short of saying he wouldn't do a deal with the current Opposition.

In a lengthy closing his party's annual conference on Sunday, Peters mentioned National about 15 times, roughly the same number he mentioned his own party.

He came into the room to billowing inspirational music, the party's members asked to stand as he walked to the stage.

While the speech was thin on policy, Peters spent most of his speech on National and its MPs, including Paula Bennett, Simon Bridges and John Key.

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"We are seeing a desperate opposition perverse new grounds and issues of dirty politics. We see in New Zealand, for the first time, a descent into fake news." 

Peters said that: "Unless they change, and we hope they do, a future National facing economic headwinds will embark on austerity policies, condemning New Zealand to more social fall out."

"We hope they change but the fact is New Zealand First, right now, as a party of the centre, is the National Party, when it had a capital N".

But Peters insisted his party was not picking sides for next year's election.

"New Zealand First will talk to any party that shares our vision for growing the country's wealth," he said.