Much to everyone’s surprise – including, it seems, his National Party colleagues – Prime Minister Christopher Luxon has committed to offering voters the chance to revisit their electoral system. Again.

Perhaps we shouldn’t be surprised – National has form when it comes to constitutional change.

Indeed, there’s a parallel between Luxon’s promise to hold a referendum on the voting system if reelected and the circumstances from which the mixed member proportional (MMP) system first emerged. Policy-making on the hoof features in both stories.

In 1978, under the old first-past-the-post (FPP) system, the National Party won an 11-seat parliamentary majority with fewer votes than the opposition Labour Party.

Unsurprisingly, at the next election – which National also won having lost the popular vote – Labour campaigned to establish a royal commission to examine the country’s electoral arrangements.

After taking office in 1984 (having won 60% of all parliamentary seats on the basis of 43% of all votes), Labour duly established the Royal Commission on the Electoral System – then proceeded to ignore its recommendations.

In the final televised leaders debate before the 1987 election, National’s Jim Bolger needled Labour’s David Lange into committing to a referendum on the electoral system if Labour was returned to office.

Lange appears to have misread his briefing notes. But Labour’s position was baked in the following day when deputy prime minister and minister of justice Geoffrey Palmer endorsed Lange’s commitment on television.

Labour’s failure to follow through on Lange’s commitment meant National could........

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