Labour plans to re-coup more than $300 million a year from multinationals.

If it gets into Government, it promises to beef up the IRD to chase those companies ducking their tax obligations, and look at changing the laws to help them do it.

The Party has sent a letter to 50 of the largest multinationals today, outlining that plan.

Revenue spokesperson Michael Wood said they have sent the letters as they'd prefer to engage with the sector in a positive way.

"We welcome multinational companies coming to New Zealand doing business here, providing products and services."

"But a part of operating in New Zealand is that you recognise you're a part of our society and when you are a part of society you contribute towards it to pay for the roads, schools and hospitals."

 Labour leader Andrew Little said in a statement: "New Zealanders are missing out by hundreds of millions, according to the IRD, because multinational companies can hide their profits in complicated international schemes".

"The fact is, many multinationals are ducking their tax obligation and leaving it to Kiwi taxpayers to foot the bill.

"This is simply not fair at a time when we need to urgently invest in hospitals, schools and housing."

Mr Wood said they would also look at changing the law to stop tax avoidance and introduce a diverted profits tax.

"The diverted profit tax acts as a penalty tax and increases your risk of not paying tax.

"So we are saying to them please play by the rules like everyone else like nurses and firefighters and plumbers and gasfitters, if you don't there will be consequences."

Mr Little said the experience in the United Kingdom has been positive.

Mr Wood said they won't sit idly until they're embarrassed into action, like the current Government.

"The point of this exercise isn't to single out any single company, it's to say that we know that we have a systemic issue in New Zealand, where even the government estimates that the sector is underpaying it's tax by $300 million a year."

The government is involved in international discussions aimed at dealing with the multinational tax issue.

Additional reporting by NZ Newswire