Finance Minister Grant Robertson has confirmed official advice warned against the minimum wage rise - which they do every time it goes up.

From today, the minimum wage has gone up to $17.70 an hour.

It's the first step on the Government's plans to increase it to $20 an hour by 2021.

Act leader David Seymour said over the weekend that official information from the Ministry of Business, Innovation and Employment warned that a minimum wage hike will lead to a loss of 8,000 jobs.

Robertson confirmed to Larry Williams that that was the information he received - but he is not concerned by those figures. 

"They also have made that prediction the last National government lifted the minimum wage as well, and it doesn't come true. We will continue to see job growth in New Zealand, I am very confident of that."

Robertson says that this is the Government fulfilling their coalition promises and enshrining their commitment to having it reach $20 an hour. 

"This is about making sure those on the minimum wage can meet those increasing costs of living."

He understands businesses will need to absorb the costs, but they have signalled this to them early so they can make their preparations.