National will tomorrow announce a $130 million welfare reform package aimed at getting people off benefits.
The party will officially launch the policy in Hamilton tomorrow but details of the plans were accidentally emailed to Sky News today.
A spokesman for Prime Minister John Key said the announcement had not been brought forward as a result of the email.
National is planning to spend $130 million, including $50m of new spending, on welfare reform. The party plans to save $1 billion by getting about 46,000 people off welfare payments.
The party's primary target is expected to be long-term beneficiaries.
The policy is National's response to the welfare working group report, which was released in February and focused on cutting the number of people on welfare by setting work obligations and handing out harsh penalties for people who did not comply.
Mr Key has previously ruled out one of the 43 recommendations made by the group, that solo parents look for paid work when their second child turns 14 weeks old, but all the other suggestions remain on the table.
The party has also already announced its youth welfare policy, under which 16- and 17-year-old beneficiaries will have their rent, power and phone bills paid directly from their benefit and will be given an eftpos-type card for groceries.