Footballers from Norway and Denmark have criticised the "cruel" working conditions suffered by labourers at Qatar's 2022 World Cup stadiums. The players, speaking in a video published by world football players' union FIFPro, said the treatment of workers had been so poor it amounted to "modern day slavery".

"We can't decide the venue for the World Cup, but we players must protest," said Norway's Tom Hogli, who currently plays for Danish side FC Copenhagen. "We cannot play football at the expense of other people."

He added: "Working conditions in Qatar are, unfortunately, cruel. They have long working days, and it's very hot.

"Safety is poor, the wages are horrible, their passports are confiscated. In many ways, they live like slaves. The football world cannot accept that."

Denmark's William Kvist, also from FC Copenhagen, added: "The fact that thousands must die to build 12 fine stadiums for us has nothing to do with football."

The video saw the players, along with board members of FIFPro, accuse Qatar of "systematic human rights violations" in relation to its World Cup construction projects.

It comes after a report by Amnesty International in March alleged construction staff working on the Khalifa International Stadium in Doha lived in squalid conditions, went unpaid for months on end and had their passports confiscated.

The human rights group – which conducted interviews with 231 migrants working on Fifa World Cup projects in Qatar – also said it had uncovered evidence of "forced labour" that saw the staff of one labour supply company use threats to force migrants to work. This included withholding pay, handing workers over to the police or stopping them from leaving Qatar.

Fifa was accused by Amnesty of inaction in relation to the working conditions in Qatar. The world football body – marred by a series of corruption scandals – said last month it would establish a body to monitor the issue.

But Mads Oland, director at Spillerforeningen and a FIFPro board member, called on Fifa to do more, adding: "[Workers'] conditions are horrible in every way. They work long hours in the heat without necessary supervision. So many die from heatstroke or cardiac arrest, often at night in the camps.

"We can avoid a situation like the one in Qatar if Fifa requires that social clauses be observed, so that the construction of highways, stadiums and other facilities is done under conditions that respect the rights that belong to wage earners."

The number of people working on World Cup sites is set to surge almost tenfold to around 36,000 in the next two years.

FIFPro's campaign – which asked the question "Must thousands of workers die for four weeks of football?" – will yet again damage the reputation of Qatar's Supreme Committee for Delivery and Legacy. The organisation, responsible for delivering the 2022 World Cup, had promised minimum standards would be met on the construction of stadiums.

Qatar World Cup 2022: Photos show the conditions faced by migrant labourers

In relation to Amnesty's report in March, Qatar's Supreme Committee accused the group of painting a "misleading" picture. It said its report was limited to just four companies out of more than 40 currently engaged on the Khalifa Stadium, and that the allegations dated back to early 2015.

Since then, it said, three companies had been banned from World Cup projects until they make improvements, while another had undergone "a comprehensive rectification process".

"The conditions reported were not representative of the whole work force," said the Qatar statement. "We wholly reject any notion that Qatar is unfit to host the World Cup."

A statement published by Fifa at the time also disagreed with the findings. Federico Addiechi, Fifa's head of sustainability, said: "We closely monitor developments and address issues through our regular contact with the Supreme Committee.

"We have also met with a number of key stakeholders to discuss the best way forward. Of course many challenges remain, but we are on the right track and committed to continue improving, to further contribute to the protection of workers' rights at the Fifa World Cup stadium projects."