"On current trends, about 50 percent more Kiwis overseas are likely to vote this year than in 2005," according to Ivan Moss, chief executive of the Kiwi Expats Association (Kea) network.
As of Wednesday, 56,152 overseas New Zealanders had enrolled to vote, and if patterns seen in previous elections are repeated, this will rise to around 60,000 by election day. This is, however, just a 10th of Kiwis living abroad.
If only 70 percent of those enrolled vote, that will make a record 42,000 overseas votes in this year's election, compared with 28,000 in 2005.A recent paper by Kiwi Alan Gamlen, working on his PhD in political geography at Oxford University, shows that relatively small numbers of overseas votes have changed previous elections.
As is well-known by even the casual student of NZ history, the overseas vote of soldiers still abroad after World War I defeated the 1919 prohibition referendum. In 1943, the overseas vote, again largely military, tipped the balance and ensured the re-election of the Fraser-led Labour Government.
More recently, Gamlen suggests that in 1993 overseas votes appeared to be "the feather that tipped the final result in National's favour" in the decisive Waitaki electorate which resulted in a National party majority of one in parliament.
"Because overseas voting patterns tend to be different, Kiwis overseas could make a real difference in this year's election," said Mr Moss.