Saudi Arabia said Wednesday it will ease key restrictions on millions of foreign workers, as part of plans to reform its long-criticised labour policy.

Human rights groups have repeatedly called on the kingdom to abolish its "kafala" sponsorship system, described by critics as a modern form of slavery that binds workers to their Saudi employers.

The ministry of human resources and social development said that from March 14, expatriates will no longer need their employers' permission to change jobs, travel or leave Saudi Arabia -- home to some 10 million foreigners.

"This initiative will improve and increase the efficiency of the work environment," the ministry said in a statement carried by the official Saudi Press Agency. "The exit and re-entry visa reforms allow expatriate workers to travel... without the employer's approval after submitting a request, (and) the employer will be notified electronically of their departure," it said.

Sattam Alharbi, a deputy minister at the ministry, said the reforms will abolish "runaway" reports against foreign workers who do not report for duty, which effectively renders them criminals at risk of being jailed and deported.

"These changes are not small changes -- it's huge," Alharbi told Bloomberg News in an interview on Wednesday. "We aim to achieve more inclusion for Saudis, attract talent, improve the working conditions, make Saudi Arabia's labour market more dynamic and productive."

However, he said the new regulations will not apply to the country's 3.7 million domestic workers.

Human Rights Watch last week said the kingdom had one of the most restrictive kafala systems in the Gulf, which it said facilitates "abuse and exploitation including forced labour, trafficking, and slavery-like conditions".

"Saudi Arabia's wealth and economy has been built on the backs of millions of migrant workers and it is time for deep-rooted change to accord them the legal protection and guarantees for their rights that they deserve," it said.

After the economic disruption that came with the coronavirus pandemic, campaigners say potentially hundreds of thousands of illegal workers remain stranded in Saudi Arabia.