Legislation under consideration in the U.S. would put an end to a program that allows thousands of international students to work in America after graduation.

The “American Jobs First” bill targets the optional practical training program, or OPT, that gives foreign graduates the right to find jobs in the U.S. for between 12 and 29 months, depending on their degree subject.

Students who studied programs in the fields of science, technology, engineering or math, known as STEM subjects, are allowed to work for just over two years after graduating.

The program has been “used to displace American workers under the guise of student training,” said a statement from the office of U.S. presidential hopeful, Ted Cruz, a Republican senator from Texas who filed the bill along with fellow Republican Jeff Sessions, a senator from Alabama.

The bill was introduced in the U.S. Congress on Dec. 10, and is the latest in a parade of legislation filed by senators from both the Republican and Democratic parties in recent weeks that is aimed at reducing the number of foreigners coming to the U.S. for work.

Some lawmakers want to curb the use of the highly-skilled work permit, known as the H-1B visa, which they say has been used to replace American workers with cheaper labor from overseas. 

Of about 133,000 Indian students studying in the U.S. in the academic year beginning fall 2014, 22% were in jobs through the OPT program, according to a recent report compiled by the Institute of International Education and the U.S. Department of State

Students can also take part in a “pre-completion OPT” to pursue a limited amount of paid work related to their major area of study during the school year and during vacations. But time spent working through that method is knocked off the time allowed for work after graduating.

Unlike the H-1B program, which currently allocates 85,000 permits a year on a lottery basis, there is no limit on the number of OPT workers authorized annually and there are no minimum wage or salary requirements.

Thousands of Indian students head out abroad every year for better-quality higher education and the number is rising.

The number of Indian students in the U.S. rose almost 30% in the year to September 2014, and over 70% of all Indian students were enrolled in engineering, math and computer science programs.

Experts attribute the rise in numbers going to the U.S. to better access to bank loans for funding and increasing confidence that they will be able to find work thanks to a better job market.