Updated 11:21am: Politically controversial changes to employment legislation are set to be passed into law later today.

MPs are due to debate changes to the Employment Relations Act that would remove a requirement for employers to conclude collective bargaining and exempt smaller business from having to guarantee continuity of employment in cases where work contracts are re-tendered.

The law change would affect worker meal and tea break rules - the government says it will introduce more flexibility in how they're taken while opposition parties argue workers' rights are being removed.

Unions question government's ERA haste

Unions are calling into question the government's vision, over sweeping changes to employment law.

The Employment Relations Amendment Bill passed its committee stage last night.

It should go through its third reading and pass into law this week.

EPMU national secretary Bill Newson questions the need for the law, saying he's seen advice that it could result in effective pay cuts.

"Is this really such the vision, the top priority of this government.

"What is the strategy for productivity? Cutting pay is not driving up productivity."

Newson says the bill seems to be solving a problem that doesn't exist.

"There hasn't been a single employer who's expressed to me some sort of dissatisfaction that needs such a dramatic change in law."

Bill Newson believes most employers would like to see the Government focus on something more important than meal breaks.