Thousands of Filipino workers stranded in Saudi Arabia due to a massive layoff triggered by a slump in oil prices have pleaded to the Philippine government to expedite their repatriation.

Some have not been paid for months and are suffering from lack of food, a migrant support group said.

Manila said last Friday a team would be sent to the kingdom, which has about 1 million Filipino migrant workers, to provide humanitarian and legal assistance.

The team, which will arrive on Wednesday, will focus on those "without food and in dire need of medical care and other support services", according to a foreign affairs department statement.

"That is the initial relief but we are telling the government to concentrate on the repatriation," Mario Ben, the head of Filipino migrants group Migrante International in Saudi Arabia told the Thomson Reuters Foundation from Riyadh.

"It is better for the workers to go home as soon as possible. They want to go back and look for jobs elsewhere again."

Ben said the repatriation should be done immediately while the Philippine and Saudi governments work out a deal to recover wages owed to the Filipino workers which are typically around $400-500 a month. Some have not been paid for up to eight months.

Saudi Arabia has seen an unprecedented influx of migrant workers during the oil boom, with the number almost doubling from 5.3 million in 2000 to 10.2 million in 2015 according to UN figures.

But the world's largest crude exporter's economy has taken a knock since late last year as a sharp drop in oil prices forced cuts in state spending.

Construction companies, hit by the downturn, have laid off tens of thousands of labourers, leaving many with no money for food let alone for tickets home.

Migrante International estimates around 11,000 Filipino construction workers have lost jobs.

According to Ben, the affected workers - who are living at company camps for migrant labourers - have survived based on support from the local Filipino community. Although aid has arrived in recent days, food remains a key concern, he said.

"Some of their children back home have also stopped going to schools because there was no remittance to send home. Their parents could not support them anymore," Ben added.

India said last month that 10,000 Indians in Saudi were facing a "food crisis". -  Thomson Reuters Foundation