The Labour Party has called on Prime Minister John Key to publicly name the National staff member the party admitted infiltrated Labour's website server in 2011.
Read more of today's coverage:
• Hager's tell-all chapters
• Patrick Gower: Key's weak link is enemy within
• Rodney Hide: Hager's 'explosive' claim a fizzer
• MP burgled and hacked
It follows yesterday's release of email correspondence between the two parties, showing National's general manager Greg Hamilton acknowledging a National Party staff member was responsible for exploiting a security vulnerability to access confidential donor and member information from Labour's databases in 2011.
"We do accept that one of our staff visited your public website ... and read files that were publicly available," the email reads.
Labour leader David Cunliffe demanded an apology from Mr Key yesterday, saying the email proved he had been "misleading" the public over the allegation, raised in author Nicky Hager's new book, Dirty Politics.