A law guaranteeing that Qatar's migrant workers get paid on time will come into force in November, legal and media sources claimed Tuesday, amid major confusion over its start date.

The Wage Protection System (WPS) -- trumpeted by the government as a "significant" reform -- had been widely expected to enter into force on August 18 after a six-month grace period for businesses to prepare for the new regulations.

But its actual start date will now be more than two months later on November 2, local daily The Peninsula reported.

It said that Qatar, which is set to host football's World Cup in 2022, had decided to postpone the launch as some in the private sector were not yet ready.

The WPS is expected to have an impact on more than 50,000 companies, The Peninsula said.

Another Qatari paper, the Arabic-language Al Sharq, also reported the November 2 start date, adding that the banking sector has completed preparations for the scheme.

Under the new system, workers will be paid either twice a month or monthly, with wages electronically transferred to their bank accounts.

Companies which do not pay salaries on time under the new regulations face fines of up to 6,000 Qatari riyals ($1,650/1,485 euros), a ban on recruiting new staff and bosses could potentially be jailed.

Michael T Palmer, a lawyer representing international firms in Qatar, told AFP that labour ministry officials had informed those in the private sector earlier this week.

"The implementation date has been verbally confirmed as November 2," he said.

This may not necessarily mean a delay from August 18, but may merely highlight confusion over the country's legislative process.

The August 18 date corresponds to exactly six months after the legislation was signed off by the emir.

However, laws cannot be enacted until publication in the "Official Gazette", in this case April 2 -- which would mean a start date of October 2.

Adding to the confusion, no start date was formally recognised when the law was published on April 2.

And under the constitution if no date is specified, an extra month is added. Coupled with the six-month grace period, this means a start date of November 2.

Failure to pay salaries on time, especially for blue collar workers, has been one of the biggest complaints voiced by rights groups against companies in the energy-rich Gulf state.

A 2013 academic study, "Portrait of Low-Income Migrants in Contemporary Qatar", found that around a fifth of migrant workers were "sometimes, rarely or never" paid on time.

The WPS has been used by the government as proof of its commitment to reform, in response to furious criticism of Qatar's labour practices since the controversial decision to allow it to host football's biggest tournament.