National Party leader John Key says he is surprised to see that the ACT Party is not standing a candidate in Waimakariri, although there had been some initial discussion about a possible deal in that seat.
ACT is not standing in New Plymouth to help out the local National candidate, in return for National's support in the Auckland seat of Epsom.
National's New Plymouth MP Jonathan Young holds the seat by just 105 votes and faces a challenge from Labour candidate Andrew Little.
Waimakariri is also a marginal seat. Labour MP Clayton Cosgrove won it in 2008 with a majority of 390 votes over National's Kate Wilkinson.
ACT will not stand candidates in either seat and Mr Key says Waimakariri has come as a bit of a surprise, as that had not featured in more recent discussions.