How is psychometric testing a Treaty breach?

The Herald reports:

The Public Service Association is taking the Inland Revenue to the employment court over its plans to use psychometric tests on employees reapplying for their jobs.

The Inland Revenue is planning to cut the number of its staff by around 30 per cent by 2021 as part of its business transformation plans.

Erin Polaczuk, PSA national secretary, said workers, many of whom had been with the IRD for years – were being coerced into taking psychometric tests just so they can reapply to keep their jobs.

“Often these ‘new’ jobs involve the same work the employees have been doing for many years.”

“If you wanted to get a good sense of a person’s skills and abilities, it would be more rational to consider the ample information stored within the department from years of performance reviews and evaluations.”

Polaczuk said the move was offensive to long-serving staff and may breach the both Treaty of Waitangi obligations and the departments compliance with the State Sector and Human Rights Acts.

How is asking employees to take a psychometric test a breach of the Treaty of Waitangi? Seriously?