Prime Minister John Key says he will take advice on allowing holidays that fall on the weekends to be taken on another day.

Labour MP Grant Robertson has said he will introduce a member's bill to address the issue.

Mr Robertson said there were 11 public holidays a year, but when Waitangi Day and Anzac Day fall on a weekend -- like this year -- they should be able to be taken on a Monday.

"We don't think that is fair, and I will be introducing a private member's bill to make sure workers get the break they deserve," he said.

Mr Key said the idea was complicated by emotive and pay issues.

"For a start off, Anzac Day is here to commemorate those who went and fought for freedom and democracy in New Zealand. Are we just saying any old day will count?"

There were also issues regarding what pay rates would apply and whether a day-in-lieu should be given for both the actual holiday and the Monday.

"Could it be resolved? Yes it could. We haven't sat down and got any advice on that," Mr Key told TVNZ.

"I'm happy to get some advice on it. I'm just saying it's a little more complex."