By 3 News online staff
The union for postal workers is accusing the National Party of carrying out privatisation by stealth.
Finance Minister Bill English says New Zealand Post, TVNZ and KiwiRail are likely to lose value over time, but the Government isn't planning to sell them off.
However, John Maynard from the Postal Workers Union claims the Government is doing its best to undermine New Zealand Post.
"Ex-Finance Minister Bill Birch is on the board of a company which directly benefits from the current Government's policy of privatising everything that isn't nailed down."
Mr Maynard says the Government is undermining the good work postal staff carry out.
"What the Government is doing and how the company is responding serves the interest of private mail companies."
He also says the removal of post boxes is "sabotage", and has had a negative impact on the level of service New Zealand Post is able to provide.