Irish holders of H-1B visas, which allow them to work legally in America, may have the visas canceled and new applicants could find the program discontinued by the Trump administration.

Close to 600 Irish obtained H-1B visas in 2015. The H-1B allows the holder to work in the US as a highly skilled employee for up to three years, with an expansion to six years usually available. Many obtain green cards subsequently.

Thousands of others from previous years are still in the US serving out their H-1B visa contracts.

However, the Washington Post reported Sunday that “President-elect Donald Trump and his choice for attorney general, Sen. Jeff Sessions (R-Ala.), have tabbed the program for a major overhaul, and might even scrap it altogether. In the House, Rep. Darrell Issa (R-Calif.) is on the same wavelength.”

When an American company cannot find a skilled enough worker in the US for a job due to labor shortage, a H-1B application can be filed for a foreign qualified worker.

However, opponents claim that the system is being abused and that many American workers are being let go and visa holders are being hired at lower wages.

The visas brings nearly 100,000 “highly skilled” contract workers, mostly in tech and mostly from India, to the United States every year.

Trump has called H-1Bs a “cheap labor program” that is subject to “widespread, rampant” abuse. Sessions has already co-sponsored legislation with Sen. Ted Cruz (R-Tex.) to substantially pare back the program.

Senator Sessions is bound to be asked about his opinion on the program during his confirmation hearings before the US Senate this week.

There may be significant blow back from Silicon Valley in particular, where the need for skilled tech workers has never been greater. Trump has made contradictory statements about wanting to help such companies while, on the other hand, discussing stopping or crippling the H-1B visa program.

Read more: Despite Trump, Irish win J-1 visa extension for three years

President-elect Donald Trump.