Ms Hipango's campaign manager Andy Jarden said he was encouraged by the National Party's early lead in the party vote.
"We're hoping for a good result in the electorate as well. But it's a bit hard to take anything out of that, because we don't know which booths have been counted.
"We think that the booths in Whanganui city are going to go marginally to Labour, but the booths outside of Whanganui will go to National. It's going to be very close."
More than 100 people are supporting a visibly nervous Steph Lewis at the Grand Hotel in St Hill St. Ms Lewis was pacing up and down, while her red-clad supporters watched results roll in.
"It's fair to say I'm quite nervous tonight. I'm excited and positive, but yeah, nervous," Ms Lewis said.
"It's going to be very, very tight, and we knew that from the start," Ms Lewis said.
Her campaign manager Josh Chandulal-Mackay said whichever way the results went tonight, it was a win for Labour in Whanganui.
"When Steph was selected in March she had a relatively low profile. But she has run an amazing campaign - she's very hard-working and has incredible energy."