Construction is booming all along Dubai's waterfront

Throughout the summer months of July and August workers in the desert state will not be allowed to work in unshaded areas between 1230 and 1630.

The measure follows international pressure to improve working conditions for the mainly foreign labourers toiling in temperatures of up to 50C.

However, many of the labourers are pessimistic about it being enforced.

Working after dark

The BBC's Julia Wheeler in Dubai says the sight of workers toiling in excruciating heat on building sites in the height of summer has been a common one across the Emirates for decades.

The construction and development boom there has been huge and continues at a rapid pace.

The migrant workers are poorly paid and have few rights

But that pace could slow down if, as Labour and Social Affairs Minister Ali bin Abdullah al-Kaabi has decreed, workers are given a break in the afternoon.

The minister is reported to have said the concept of workers labouring under the hot sun is not part of the religion or culture of the UAE.

He says there are another 20 hours a day that the labourers can work.

But the building contractors say it is not feasible or safe for work to be done after dark and many residents would be angry at being disturbed in the evening.

Groups supporting workers' rights are also concerned there are not enough inspectors to ensure compliance.

And even if the promised fines are imposed for breaking the ruling, these may not be enough of a deterrent when compared to the penalties the contractors could face for late delivery of projects - many of which have been commissioned by the government, our correspondent says.

Many of the workers come from South Asia and although politely described as "guest workers", they are poorly paid by international standards and have few rights.

Our correspondent says there are regular tales of labourers not being paid for months on end by their employers.