Prime Minister John Key has signalled big infrastructure spends in Auckland will be the centrepiece of his State of the Nation speech on Wednesday, but was staying mum on whether that included fast tracking the City Rail Link.

Mr Key will deliver his speech to the Auckland Chamber of Commerce on Wednesday.

"As New Zealand's largest city, our biggest commercial centre and the main gateway for international tourists, we all need Auckland to succeed."

He said the Government was already putting billions of dollars into Auckland as it grew and he would highlight some of the priorities for the year ahead.


"It's a speech that looks very heavily at infrastructure projects, not just in Auckland, but it does look at those issues and gives the Government perspective on next steps."

He said people would have to wait for his speech to find out the specifics.

There has been speculation Key will use his speech to announce the Government will start funding works for the $2.5 billion City Rail Link in 2018 -- two years ahead of schedule and touch on other projects such as the second harbour crossing.

The Government has come under pressure for its handling of the growth of Auckland and Mr Key said better infrastructure was needed.

"We are spending billions and billions of dollars as a Government on infrastructure. So the announcements we make tomorrow will ultimately mean the Government increases even further its expenditure on infrastructure. We are doing that because that infrastructure underpins the efficiency and competitiveness of our economy. We are not doing this because we need to stimulate the economy per se."

Mr Key said housing in Auckland was a focus for the Government, but it was not the main issue of his speech. "We are saying we need to build more houses faster. It is our expectation the demand in Auckland is going to continue, that the growth in the Auckland population is going to continue and we just need to build a lot more houses between now and the next five to 10 years."

He said that process should be as smooth as possible and measures such as the Resource Management Act reforms would help.

Everything you need to know

What is the PM doing in Auckland today?

The Prime Minister is in town to deliver his annual State of the Nation address. He is expected to bring forward Government funding for the $2.5 billion City Rail Link(CRL) to 2018. He may announce progress of an east-west road connection between Onehunga and Mt Wellington, the $380 million Penlink highway connecting Whangaparaoa to State Highway 1 and a new harbour crossing.

What is the City Rail Link?

A 3.4km rail tunnel up to 42m below ground from Britomart to Mt Eden will have two new stations, Aotea and Karangahape Rd. The link is costed at $2.5 billion and, according to Mayor Len Brown, will have wider economic and environmental benefits beyond the central city. Britomart, which can handle 20 trains an hour will become a through station handling 48 trains an hour.

How will Auckland benefit from the Government coming on board the CRL earlier?

Bringing forward funding from 2020 to 2018 will make financing of the project much easier for council. The council hopes the Government will pay half the $2.5 billion cost, but that remains to be seen. If the Government only pays a half share from 2018, its share will be about $1 billion and the council will pay about $1.5 billion. The completion dates remains at 2023.