Another business has been "named and shamed" over its use of the 90-day employment law, but the business is sticking to its guns, saying it respects employees but needs flexibility on the odd occasion staff don't fit the bill.

Unite Union's "utu squad" today said Burger Fuel in Auckland's Mission Bay had sacked a young staff member on the 89th day of the 90-day trial period after she asked for her work break entitlements to be better respected.

The employee, Joanne Bartlett, told NZPA she received a letter in April saying her boss was exercising his right to dismiss her and could she please return her hat and t-shirt.

Ms Bartlett said she was a diligent minimum-wage worker, but had concerns about not getting her entitled breaks on certain shifts.

Being on a trial period had made her reluctant to make too much of an issue of it as there was constant anxiety of losing her job hanging over her head. When she pressed for an explanation she got a "half-arsed" reply suggesting she wasn't the right fit for a long-term role.

She said she felt exploited. "They worked me until the 89th day and then said goodbye. If you knew my working wasn't up to standard you wouldn't have waited for the second to last day."

Management at the outlet, which was the target of a union protest today, didn't want to comment, but company chief executive Josef Roberts said in the end the franchisee made a decision on whether or not to proceed with keeping the employee on.

Mr Roberts said everyone was entitled to their breaks, which differ between full and part-timers, but there was also an expectation that employees step up and work during busy periods.

"We have a certain culture and a certain standard and sometimes it really does take two or three months to sort out if someone is going to be the right person," he told NZPA. "With other people you will know a lot quicker. The 89th day was perhaps seemingly unfair, but it's a deadline where an employer has the final day to say if it's right to proceed or it isn't."

Mr Roberts said the 90-day rule was an important tool for employers. "Every state in Australia has this - and they are a far more unionised country that we are - so we are just catching up. I think we need to have this doesn't always work out with people and you do need the ability to have some flexibility at times."

He said the company's employment relations record was good and it was rare to see stoushes.

Under 90-day employment laws, businesses with fewer than 20 staff can dismiss workers within that time without the prospect of a legal challenge. The Government is now pushing legislation through Parliament which will extend that to all business, along with other employment law changes.

Unions are fighting hard against the changes, along with opposition parties, and union-led rallies are planned in the main centres throughout New Zealand at the weekend.