It will be an invitation they cannot decline even though they know the meat and vegetables are not the only things that are going to be roasted that evening.
David Cunliffe's avowed intention, should he become prime minister, to haul the corporate shareholders in what was Pike River Coal up to Premier House to twist their arms to pay compensation to the miners' closest and dearest is more than a tad unconventional.
The Labour leader is deadly serious, however. He insists that he would instruct the Treasury to pay the $3.5 million which is currently owed to the families by way of court-ordered reparation for health and safety failings at the mine. He would then use all the means at his disposal as prime minister - be it private tete-a-tetes or even legislation as a last resort - to ensure the Treasury got the money back in full from the shareholders who for too long have ignored their moral obligations.
Mr Cunliffe had sought to breathe life into the matter of compensation the previous week, but with little success. Last Tuesday was the third anniversary of the explosion at the mine, however. That provided the platform for him to warn the likes of New Zealand Oil and Gas and other companies and individuals who had a stake in Pike River Coal prior to the company going into receivership to stump up with the cash even though technically they are not liable.
Not only had Mr Cunliffe gained the political initiative over National, he noted the governing party's reluctance to take a similar line to Labour and instead look for reasons (or excuses) not to force the payment of compensation.
He sought to portray that reluctance as another example of how John Key's five-year-old administration has lost its ''moral compass'' and is only interested in doing things which help National's big business mates who fund that party.
Labour this week levelled similar accusations of loss of moral compass at Mr Key and Foreign Minister Murray McCully for sacrificing New Zealand's proud record of upholding human rights so that they could digest canapes and quaff Champagne at last weekend's Commonwealth summit and cuddle up to the repugnant Sri Lankan Government and be rewarded for their softly-softly diplomacy with the gift of an elephant for Auckland's zoo.
Do Labour's claims really stack up in both cases? With regard to Sri Lanka, much was made of the decision by Canadian Prime Minister Stephen Harper to boycott the summit because of what he said were ongoing reports of intimidation, incarceration, disappearances and killings of Tamils in the country's north and the Sri Lankan Government's failure to uphold the Commonwealth's core values which were ''cherished'' by Canadians.
Mr Key came under pressure to follow suit. Yet in Canada, there was much suspicion Mr Harper had opted not to go to avoid upsetting the Canadian Tamil community. Around 300,000 Tamils of largely Sri Lankan origin live there and Tamils make up as much as 7% of Toronto's population. Their votes might swing the outcome in marginal seats at election time.
Mr Harper has also come under fire for preferring isolation over engagement with a regime that fails to meet acceptable democratic or human rights standards.
Under Mr McCully's watch, New Zealand's foreign policy has shown a preference for engagement, especially with regimes, such as the one in Burma, which have accepted some degree of political reform is necessary in order to lift economic performance and trade.
Mr Cunliffe has said that had he been in Mr Key's shoes, he would have gone to Colombo, but only to ensure a country other than Sri Lanka was installed as chair until the next summit in two years.
Unfortunately for Mr Cunliffe, the Commonwealth possesses neither the mechanism nor the inclination to punish and embarrass its host that way.
Mr McCully revealed in Parliament this week New Zealand was not as soft as many assumed. It supported some form of war crimes inquiry as mooted by Britain's Prime Minister, David Cameron. New Zealand believed those responsible for the deaths of thousands in the north should be held to account, just as there should also be reconciliation after the civil war, along with devolution in the north.
As for Pike River, the claim National has been heartless has to be set against the $5 million that ACC will have paid to the miners' families by the end of next year and the Government spending $7 million on a mine re-entry to recover bodies.
National has tried to get Mr Cunliffe to explain why he thinks a death in one particular workplace should be treated in a far more favourable financial light than a death in another - important because Labour has been pushing for an inquiry into safety in the forestry industry.
National also wants Mr Cunliffe to explain how a lump-sum compensation payment would square with ACC's ban on going to court to sue for damages. There is already a precedent, though. The Government paid $2.7 million in 1997 settling claims from the Cave Creek platform collapse.
Mr Cunliffe has wisely avoided swallowing the bait and getting into an argument he might lose.
The strongest sign he is winning came in a cartoon in Wellington's Dominion-Post newspaper this week portraying the Government as a crocodile shedding tears while chewing up a document entitled ''Pike River Families Compo''. That said it all. Well, not quite. It is hard to envisage Mr Key tolerating taunts from Mr Cunliffe regarding Pike River from here until election day next year. Time for some prime ministerial pragmatism over principle?
- John Armstrong is the political correspondent for The New Zealand Herald.