ROME— Pope Francis on Thursday condemned employers who only offer temporary contracts or no health insurance to employees, calling them “bloodsuckers,” and saying they exploit those who desperately need a job by turning under-the-table payment into “civilized slavery.”

“Those poor people become slaves. We think of the here and now, the same thing happens all over the world,” Francis said in daily homily.

The pope complained of “rich people who exploit others,” saying they offer contracts only from September to June, and then the employees have to “eat air” from July to August.

“Those who do that are true bloodsuckers, and they live by spilling the blood of the people who they make slaves of labor,” Francis said, according to a summary of the homily provided by Vatican Radio.

As an example, he quoted the example of a young girl who once told him about having a job that paid 650 euros (circa $700) a month for an 11-hour a day, under the table, and if she didn’t take it, someone else would because “there’s a line of people waiting.”

These exploitive employers, Francis warned, “grow fat on their riches.”

All around the world, he said, workers who lack better opportunities in the labor market accept under-the-table employment, even though it means being left without basic protections, such as unemployment insurance, workers’ compensation, or access to healthcare.

Statistics of under-the-table employment are considered woefully inaccurate, among other reasons because those hired are unlikely to report it, especially in the case of undocumented immigrants.

However, several studies estimate that in so-called developed countries, at least 15 percent of the workforce is made up by this informal economy. A report from 2006 shows that in the United States, between 80 to 97 percent of nannies and private household employees were paid under the table, and the numbers aren’t much better for temporary jobs such as construction or home repair.

In Pope Francis’ backyard of Latin America, estimates hold that informal employment represents up to 51 percent of the total workforce, while in India and many sub-Saharan African countries the number goes up to 90 percent.

The pontiff called all this a “civilized” kind of human trafficking, the third largest illegal industry in the world, after the drug trade and the arms trade.

“May the Lord make us understand today the simplicity that Jesus speaks to us of in the Gospel of today: a glass of water in the name of Christ is more important than all the riches accumulated through the exploitation of the people,” Francis said.

The pontiff also referred to his Wednesday meditation on the parable of the rich glutton and Lazarus, comparing that situation to under-the-table employment. He regarded the latter as much worse, because the rich man from the parable “didn’t realize, and left the other man die of hunger.”

“But this is worse,” Francis said. “This is starving the people with their work for my own profit! Living on people’s blood. And this is a mortal sin. This is a mortal sin. And this demands a great deal of penance, a great deal of restitution, in order to be converted from this sin.”

The pontiff said that Thursday’s reading, from a letter of St. James warning the rich who accumulate wealth by exploiting people, is one that applies to present day.

“We might think that slaves no longer exists: they exist,” Francis said. “It’s true, people no longer go to Africa to capture them in order to sell them in America, no. But it is in our cities. And there are these traffickers, these people who treat the working people without justice.”

Estimates show that in present time some 27 to 30 million people are affected by modern commerce in human beings, enslaved because they’re physically confined or restrained and forced to work, or controlled through violence.

This means that there are more slaves today than were seized from Africa in four centuries of the trans-Atlantic slave trade.

Francis also reflected on the so-called “theology of prosperity,” a belief among some Christians that God’s will for them is financial blessing, which can be achieved with faith, positive speech and donations.

According to the pontiff, those who follow it are mistaken.

“Riches in themselves are good,” Francis said, adding that they’re “relative, not absolute” goods.

Insisting that one can’t serve both God and wealth, riches become “chains” that take away “the freedom to follow Jesus.”

In the reading, St James writes, “Behold, the wages you withheld from the workers who harvested your fields are crying aloud; and the cries of the harvesters have reached the ears of the Lord Almighty.”