New Zealand First leader Winston Peters has warned pensioners not to believe National Party promises on superannuation.
National Party leader John Key has promised to resign if his party cuts superannuation.
Mr Peters told a Grey Power election meeting in Porirua on Tuesday that despite Mr Key's promise, retired people should not trust him.
He attacked National's record, saying that when National was in government it cut superannuation to 60 cents in the dollar.
Mr Peters said only New Zealand First could be trusted to look after the elderly.
National MP Katrina Shanks told the meeting Mr Key's promise was genuine, and there would be no change to superannuation.
Another potential ally of National after the election, the United Future Party, also expressed reservations about its trustworthiness.
One of its candidates, Murray Smith, said that if National were able to govern alone, it could break its promises.
