 Meanwhile, the Prime Minister has waded into the living wage debate, saying Labour's leadership hopefuls are dreaming if they think they can afford it. Both Grant Robertson and David Cunliffe have announced the pay hike policy, but as time for O'Brien reports, even their match numbers don't match up. These are the people that clean up after MPs. They earn little more than the minimum wage. Grant Robertson and David Cunliffe want to give them a pay rise by introducing a living wage, a near $5 bump on the minimum. The people who believe that we can do that with no implications for the economy also believe the Easter Bunny is going to turn up next year and he won't. Cunliffe would introduce it immediately for the public sector at a cost of $25 million for just the first year. Government contractors would come later. Most people would be surprised just how low public sector wages are. They're not policy people on fat salaries in Wellington. Robertson's plan is different. It's more of a pledge, a promise to develop, a timeline to roll out the living wage. The win would depend on the cost and he believes he can do more with the money than Cunliffe spending the same, but including the public sector and contractors. One of those has to be wrong. Not mine. Once we know the full cost, we'll decide how long it will take, but we have a clear goal. We've double checked our figures. I think we're the only campaign to have done a costed estimate. They clearly have no understanding of economics. Cleaning contractor Crest Clean chooses to pay all of its staff a living wage, but says Labour's got the wrong approach. Well they're just promising as an overnight step up. I'm talking about over a period of time upskilling our employees, the people of New Zealand to achieve greater output. It'll be a popular policy for both candidates, but uncosted policies can backfire. This one will be thoroughly tested through two elections. Tovah O'Brien, 3 News.