New Zealand First is pushing for Closer Commonwealth Economic Relations (CCER) between New Zealand and the United Kingdom.
Party leader Winston Peters said a trade deal with the UK is an absolute priority.
"In the wake of the 'Brexit Vote', New Zealand must be the first country in the queue for a trade deal with a liberated United Kingdom," he said.
"We already have the model of Closer Economic Relations (CER) with Australia... adding the UK would begin to transform this into Closer Commonwealth Economic Relations."
Peters said CCER is the means to bring in other Commonwealth states.
"Britain's exit from the European Union within the next two years is the spark CCER needs to get it going. What's more, Boris Johnson has spoken in favour of a similar concept," he said.
Former London Mayor Boris Johnson previously said Britain must look beyond the European Union and rekindle its relationship with Commonwealth countries.
In an interview with the Telegraph, Johnson said the UK must have a "truly global perspective".
"We betrayed our relationships with Commonwealth countries such as Australia and New Zealand, and entered into preferential trading arrangements with what was then the European Economic Community," he said.
"We need to raise our eyes beyond Europe, forging and intensifying links with countries that are going to be growing in the decades ahead - countries that offer immense opportunities for British goods, people, services and capital."
Trade between Commonwealth countries is estimated at over $680 billion today.
The combined gross domestic product of Commonwealth countries is predicted to hit US$14 trillon by 2020, Peters said.
"CCER is about real free trade. There will be none of this Investor State Dispute Settlement nonsense because as Commonwealth countries we share similar legal systems," he said.
Peters previously said he believes New Zealand's trade agreement with Australia, CER, provides the ideal template for Closer Commonwealth Economic Relations.
He said it could become a model for a high quality future agreement not just with Britain but with Canada, South Africa and India.