Employers will no longer be able to opt out of multi-employment collective agreements and will be bound by a duty to conclude negotiations in good faith under changes to employment law.

But Workplace Relations Minister Iain Lees-Galloway says good businesses will have nothing to fear and will benefit from stronger conditions for workers.

The duty to conclude is one of several measures in the new legislation, announced today, that the Government hopes will strengthen collective bargaining and ultimately lift wages.

It was scrapped under the previous Government, and businesses have expressed concern that reinstating it might mean that unions could essentially force employers into collective agreements.

But Lees-Galloway said only one employer had tried - unsuccessfully - to use the provision of not having to conclude negotiations.

"The vast majority of employers have not needed to use that provision because they are good employers who want to stay at the table and reach a conclusion. The fact only one employer [has] used it speaks volumes as to why we don't need to have it in our legislation."

That case was Affco, which appealed the case to the Supreme Court. Last September the court rejected the appeal and found that the meat processor had unlawfully locked out meat workers when collective bargaining was taking place.

Lees-Galloway said not changing the law would leave the door open to treating unions unfairly.

"It would leave an option open to employers who simply do not want to have unions in their workplace. Sometimes you have to legislate to keep some of the fringe operators honest."

The Government's bill, announced by Prime Minister Jacinda Ardern, includes several other measures aimed at empowering workers.

After lobbying from New Zealand First, the controversial 90-day trial will be kept, but will only be available to businesses with fewer than 20 employees.

All employers will still be able to use probationary periods which, unlike 90-day trial periods, do not allow for unjustified dismissal.

It comes as small-business confidence has plunged to its lowest level in nine years. According to ANZ's quarterly Business Micro Scope survey, 29 per cent of small businesses were more pessimistic about the year ahead, a net fall of 43 per cent from the previous survey.

Others measures in the bill include:

• Guaranteed rest and meal breaks
• Ability to engage in low-level industrial action without the threat of pay deductions
• The right to the same conditions as other workers on a collective agreement, if you're a new worker
• Guaranteed pay and conditions, if you're a vulnerable worker and your employer changes
• A requirement to include pay rates in collective agreements
• A requirement for employers to pass on information about unions to prospective employees 
• Greater protections against discrimination on the basis of being a union member
• Removing the ability of employers to opt out of multi-employer collective agreements

A union will be able to:
• Reasonably access a workplace to initiate collective bargaining
• Be given reasonable time in a workplace to conduct its duties

The bill is expected to have its first reading just before the 100-day period expires on February 3.

Lees-Galloway said the new rules around rest and meal breaks will include exceptions for workplaces such as air traffic controllers, where it was not practical for workers to take breaks at the same time.

"[The bill] sets some very tight criteria. Very few businesses will qualify, but it tries to address exactly the issue raised by air traffic controllers."

The bill aimed to strengthen collective bargaining, lift union numbers and ultimately lift wages, as part of a wider Government programme.

Three aspects of the Government's 100-day manifesto have been given longer timeframes. They are:

• Restoring the right of film and television workers to collectively bargain
• Removing the automatic passing on of collective terms and conditions to non-union workers
• Providing foreign workers working for foreign companies in New Zealand the same protections, such as minimum wage rights, as New Zealand workers.

Lees-Galloway has previously announced a joint working group to work through the issues around the so-called "Hobbit law" in the film and television industry, but they were not expected to be resolved by the 100-day deadline.

He said the automatic passing on of terms and conditions had technical issues and was now in the 12-month programme.

The Government still wanted to ensure foreign workers in New Zealand had employment protections, in response to Chinese engineers who came to New Zealand to work on locomotives purchased from China, but who were not paid properly.

"We're looking at a different way of achieving that rather than legislation," Lees-Galloway said, adding that he was confident of resolving any issues the policy may raise around free-trade deals.

Other workplace polices have already been put into law, such as lifting the minimum wage to $16.50 an hour by April, and extending paid parental leave to 26 weeks by 2020.

"For the past 30 years, working people have received a diminishing share of economic growth, and we're trying to restore some balance," Lees-Galloway said.

"It is certainly my hope that by giving unions more tools to be able to better represent their members and bargain for better wages that the proposition of joining a union will look a lot better."

The Government still plans to abolish youth rates, but that is in the body of work to be completed in the next 12 months, along with industry-wide fair pay agreements.