[Source: Reuters]New Zealand Prime Minister ‌Christopher Luxon said he was open to a referendum on whether to change the country’s electoral system, opening another split in his centre-right coalition months ahead of a general election. New Zealand adopted the German-style Mixed Member Proportional (MMP) system in 1996 after an inquiry found smaller parties ​were being shut out of parliament under the previous first-past-the-post system. Article continues after advertisementWinston Peters, the leader of New Zealand First, a minor party in Luxon’s National-led coalition, called the idea “inexplicable”. New Zealand last ​voted to retain the system in a 2011 referendum, with 58% of voters in favour. In the interview Luxon also reiterated support for extending New Zealand’s ​current three-year fixed-term parliaments to four years.