Labour will introduce a member's bill to ensure holidays that fall on a weekend can be taken another day.
New Zealanders will miss out on two of 11 public holidays this year because Waitangi Day is a Sunday and Anzac Day falls on Easter Monday - already a statutory holiday.
Labour MP Grant Robertson said the holidays should be able to be taken on a Monday in such instances.
"This year, New Zealanders will only get nine of the 11 public holidays they are entitled to under the Holidays Act, because Waitangi Day and Anzac Day fall on the weekend or clash with another holiday," he said.
"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.
"Anzac Day and Waitangi Day are of great importance. It is important that we continue to commemorate the days on the 6th of February and 25th of April.
This bill will not change that, but it will restore to New Zealanders the holidays they deserve."
Mr Robertson said Anzac celebrations in Australia were held on the actual day but a public holiday was also held on a Monday.
"Waitangi Day and Anzac Day are the only holidays that are not protected under the act. Given that the situation only arises two out of every seven years we believe that it will be relatively easy for businesses to absorb the costs and in doing so ensure that workers get a fair go."
Labour leader Phil Goff said the party had not moved to change the law while in government because it was focusing on legislating for four weeks' annual leave.
However, the bill will first have to be drawn from the ballot and then require the support of Act, the Maori Party and the Greens to pass into law if National does not support it.
A buoyant Labour Party held its first caucus of the year yesterday at Auckland's Waipuna Lodge, ending a big week in politics with a barbecue at Mr Goff's Clevedon farmlet last night, where Cyclone Wilma forced guests to retreat into the barn but did not dampen the mood.
With a caucus reshuffle possible by as soon as next week, Mr Goff ended the week in a perky mood, seemingly confident Labour would finally start to close the gap in the polls on the back of National's plans to sell off minority stakes in some energy SOEs and reduce its shareholding in Air New Zealand.
Mr Goff said the election would effectively be a referendum on the state asset sales policy and the Prime Minister's comment that he expected to go through with it even if it was unpopular with the public was "nothing short of arrogant"."
"Key's speech has created a very clear differentiation and one that is going to work very strongly in Labour's favour because we believe we represent the view of most New Zealanders on this situation. Our caucus members are going into the election knowing this will be a far more traditional contest than might have been expected a year ago," he said.
"The National Party is revealing its true colours and we've seen these colours before and they've been rejected by New Zealanders before."
But Mr Goff is also having to defend his own new tax policy from claims by analysts and National that Labour would have to borrow to fund its estimated $1.3 billion cost.
He rejected claims that Labour would have to raise the tax rate for those earning more than $120,000 to almost 60 per cent if he was to offset the cost of the "no-tax zone" policy.
But he refused to say how high Labour was willing to go and would not rule out over 40 per cent.
On the reshuffle, Mr Goff said at least five places were opened up by the resignations of Pete Hodgson, Lynne Pillay, George Hawkins and the exit of Chris Carter and Winnie Laban. Nanaia Mahuta is understood to still be considering her future.