Mr Nowak described the laws as: “a product of a desperate Conservative Government spoiling for a fight with unions to distract from their dire economic record.”
The Strikes Act came into force earlier this year, and mandates a minimum level of staffing for key public services such as health, fire and education.
Unions criticised the bill as an infringement of workers’ rights, and the government suffered defeat in the High Court on a key provision earlier this year.
The bill sought to repeal section 7 of the Conduct of Employment Agencies and Employment Business Regulations (2003) which made it illegal to replace striking workers with agency staff, or to use agency staff to replace non-striking workers who had been moved to other departments to cover strikes.
However, the rationale was based on a 2015 consultation and was struck down by the court.
Mr Nowak told a news conference in Liverpool: “The ILO has already slapped down the UK Government and ordered it to make sure existing and prospective legislation is in line with ILO standards.
“We believe the Strikes Act falls well short of that, and that’s why we have submitted a case to the ILO over these new laws.
“Unions defeated the Government in the High Court over the unlawful use of agency workers during strikes. We are determined to win again.
“These laws haven’t been designed to resolve conflict at work, they’ve been designed to escalate it.
“They’re unworkable, undemocratic and almost certainly in breach of international law.
“They’re the product of a desperate Conservative Government spoiling for a fight with unions to distract from their dire economic record.
“The Strikes Act is the nadir of the Conservatives’ wretched record on living standards and rights at work.”
A Government spokesman said: “The purpose of this legislation is to protect the lives and livelihoods of the general public and ensure they can continue to access vital public services during strikes.
“The legislation does not remove the ability to strike, but people expect the Government to act in circumstances where their rights and freedoms are being disproportionately impacted, and that’s what we are doing with this Bill.”