By CAMILA DECHALUS and DEAN DECHIARO

A provision in the GOP tax overhaul bill unveiled Thursday would require all taxpayers claiming the federal child tax credit to use a valid Social Security number, rather than the tax identification number used by undocumented immigrants with children who are U.S. citizens.

Under the measure, all taxpayers would be required to provide a work-eligible Social Security number to claim the refundable portion of the child tax credit or the American Opportunity Tax Credit. Similar legislation was introduced in January by Republican Policy Committee Chairman Luke Messer of Indiana, with the aim of preventing undocumented immigrants from claiming the $1,000 tax credit with their Individual Tax Identification Numbers (ITIN).

Messer has said the change is needed to cut down on fraud and abuse and to end what he characterized as a “reward” for people who came to the country illegally. He cited a 2014 report by the Treasury Department’s inspector general for tax administration that estimated undocumented immigrants were receiving between $5.9 and $7.1 billion each year from the credit.

“We can’t continue to reward people who come to our country illegally, while those who work hard and play by the rules struggle to get ahead,” Messer said on the House floor in October. “My legislation would stop billions of taxpayer dollars from going to illegal immigrants by eliminating a loophole in our tax code.”

The tax bill would increase the child tax credit from $1,000 to $1,600 per qualifying child, according to a bill summary. The measure also includes a new family credit that includes a $300 credit for each parent and non-child dependent, as a way to help with everyday expenses. 

“It’s well past time to address both our broken tax code and an immigration system that rewards people who come here illegally,” Messer said in a statement. “Our broken tax and immigration systems continue to incentivize immigrants to come here illegally. Closing this loophole will steer us back to rule of law, ensure tax benefits like this are reserved for American citizens and save us billions of dollars.”

Watch: White House Mood ‘Guarded’ as Tax Push Looms

David North, a fellow at the Center for Immigration Studies, which advocates for tougher immigration laws, said the provision’s inclusion in the tax bill was “more sensible than building a wall across the U.S. and Mexico border.”

“This is a sensible option because the amendment doesn’t cost the United States money, in fact actually saves us money,” he said. “Congress is cutting off more techniques that allow illegal aliens to benefit from the U.S. government.”

The Joint Committee on Taxation estimates this provision would increase revenues by $23.1 billion between 2018 and 2027, the bill summary says. 

Critics of the provision say it’s in line with President Donald Trump’s hawkish immigration policies.

“This amendment is entirely based on anti-immigrant support,” said Charles Wheeler, director of training and legal support at the Catholic Legal Immigration Network. “Republicans are looking for ways to save money for the government and it won’t work.”

Wheeler, who has worked to protect the rights of immigrants for 21 years, said the legislation will negatively affect children. 

“I think the real downside will be to the children who will not be financially supported by their parents because they do not have access to claim child tax credits,” he said.

Meg Wiehe, deputy director at the Institute on Taxation and Economic Policy, said the provision would harm more than 5.1 million children — the majority of whom are U.S. citizens or young “Dreamers” brought to the country illegally when they were children.

“Their undocumented parents are hard-working taxpayers, paying not only state and local taxes as ITEP as documented, but also federal taxes including the payroll tax,” Wiehe said in a statement. “Investing in the economic security of these children through access to the Child Tax Credit recognizes their parents as hard-working taxpayers, helps families pay for basic needs such as food and utilities, and benefits the economy and well-being of the children.”