The Airport Security staff who have called a strike earn between $53,000 and $64,000 a year and have turned down an offer of 2 percent annual payrise over three years.
Staff at the upper end of the payscale, which the employer says most union staff are on, would have their pay bumped up to almost $68,000 by the third round of increases.
The 2 percent payrise is in line with what other public sector unions have accepted - such as nurses, police and teachers.
Currently the staff earn $53,136 - $64,107 and have a package that includes a transport allowance, free car parking and a "wellness payment".
Here's what was on offer:
The unions have turned down two offers that have included abolishing the package of allowances - which is the real sticking point in negotiations.
If the unions took this offer - the first year the staff at the top would receive $65,297 plus the $6000 cash, the second year, they'd get $66,603 and by the final round of increases the upper end of salaries would reach $67,935.
Salaries and Allowances:
The Aviation Security staff are planning strikes at three of the country's largest airports later this month, some during the school holidays - but Aviation Security Service has now countered the action threatening a lockout.
Three unions, E tū, the Public Service Association (PSA) and the National Union of Public Employees (NUPE) have been negotiating contracts with their employer, Aviation Security Service (AvSec) for 10 months.
Most AvSec staff are unionised - about 80-90 percent. The negotiations haven't resulted in a deal that E tū or the PSA are happy with - however NUPE has accepted the employer's second offer.
Since E tū and the PSA haven't accepted the deal - it's now resulted in strike action - rolling strikes will take place from Wednesday 20 July to Wednesday 27 July for three hours at a time at Auckland and Wellington Airports.