The government is expecting a final decision overnight about whether the European Union will formally approve free-trade agreement (FTA) negotiations with Australia and New Zealand.
The agreement will pave the way for a multi-billion dollar deal before the United Kingdom leaves the EU in March.
Plans for "fast-tracked" FTA negotiations were announced by European Commission President Jean-Claude Juncker during his annual State of the Union address to the European Parliament in Strasbourg in September.
Australian media are reporting the mandate will be approved.
Trade Minister David Parker said he expected to hear from the EU about a decision after the council meets overnight, New Zealand time.
The deal, based on EU modelling, could result in billions of extra dollars in trade for New Zealand each year, Mr Parker said.
"So it's very, very significant and that flows through to more jobs and higher incomes for New Zealanders."
Of the $20 billion of two way-trade, about $4bn would go to the UK, so European markets were "huge, high value markets", he said.
"This is probably one of the best deals that we could do in the world.
"It's been hanging in the balance even until very recently.
"We don't count anything until it's done, so no we don't count our chickens until they've hatched."
Two way trade with the EU, including the United Kingdom, is currently worth about $20 billion.
The EU estimates an FTA could result in a GDP boost for New Zealand of between $1.2bn and $2bn, and a 10 to 20 percent increase in exports.
The sectors likely to benefit most from a FTA with the EU include agriculture, motor equipment, machinery, processed foods and services.