FIRST ON FOX: A broad coalition of hawkish immigration groups and former Trump-era officials are urging Congressional Republican leaders to unite their members behind a robust "flagship" border security bill for the next Congress – saying the sweeping legislation would end the border crisis and act as an initial step for further immigration reforms.

In a letter, obtained first by Fox News Digital, 16 groups and a dozen former senior Trump officials urge the leaders to unite behind "flagship introductory legislation" in the upcoming Congress next year when they believe Republicans will have taken control of the House and Senate.

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"When the 118th Congress opens with new majorities in both chambers, it will be in large part because Americans have rejected the Biden administration’s purposeful dismantling of our nation’s borders and our immigration enforcement infrastructure," they write.

"Congress should be emboldened with the mandate to immediately legislate unflinchingly, ensuring that neither this nor any future administration is again able to weaponize loopholes in the immigration system—and defiantly refuse to follow plain law—to purposefully drive mass illegal immigration to the United States," they say.

The signers warn that "the opportunity to legislate has been missed in several previous Congresses, but the stakes are too high for it to be missed again." They say that just increasing resources or restarting border wall construction will not be enough to solve the crisis, and instead it must target long-standing loopholes in the immigration and asylum system.  

"While those are important measures required to secure the borders, without closing the loopholes and other changes, the Biden Administration’s policies will continue to act as a powerful magnet, attracting millions of illegal aliens into our country," they say. "To retake control of our border and properly address what is sure to be an electoral mandate, we urge you to unite behind flagship introductory legislation for the upcoming Congress."

The letter calls on leaders to "exclude amnesty of any type," to create an immediate expulsion authority, clarify that migrants are ineligible for asylum if they came through a safe third country, restrict prosecutorial discretional and reform the Trafficking Victims Protection Reauthorization Act (TVPRA) which has been blamed by many officials for encouraging the surge in unaccompanied children in recent years.

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The list of legislative proposals includes the completion of the border wall, the raising of the "credible fear" standard for asylum, increased resources for Customs and Border Protection (CBP) and Immigration and Customs Enforcement (ICE) – specifically for deportation officers and detention beds. They also include a full implementation of the Trump-era "Remain-in-Mexico" policy, to clarify that gang violence and domestic violence are not grounds for asylum, and for states to be allowed to have the authority to participate in immigration enforcement.

Groups on the letter include the Federation for American Immigration Reform (FAIR), the Heritage Foundation, Numbers USA, America First Policy Institute, Center for Renewing America, Judicial Watch, and the National Border Patrol Council.

Former officials who have put their name to the letter include former acting DHS Secretary Chad Wolf, former acting Deputy Secretary Ken Cuccinelli, former Border Patrol chief Rodney Scott, former White House Chief of Staff Mark Meadows, former acting ICE Director Tom Homan, former acting CBP Commissioner Mark Morgan, former Office of Management and Budget Director Russ Vought and former Ambassador to Mexico Chris Landau.

The letter comes amid continued concern about the flood of illegal migration at the southern border, which has hit historic highs and is expected to continue to surge in the coming months when the Biden administration ends the Title 42 public health order, which has been used to quickly expel migrants at the border. There were more than 221,000 migrant encounters in March alone and that is expected to have risen in April.

Migrants Texas

May 5 2022:  A migrant family sits after being processed in Roma, Texas.  (Photo by Brandon Bell/Getty Images)

"These are the fixes that, if enacted and enforced, would end the border crisis. Ending the border crisis will be a mandate from the American people," the signers say. "This is how you do it."

The reforms, now being proposed by a powerful coalition of immigration and border security groups and former officials, represents the strongest and most detailed push to date of a restrictionist answer to the crisis at the border. 

The Biden administration and Democrats in Congress have pushed their own version of immigration reform, efforts which have centered a mass amnesty for millions of illegal immigrants and an expansion of legal pathways to U.S. entry -- but failed due to a lack of support from Republicans. This legislative proposal, which explicitly contains no amnesty, would represent an ambitious Republican alternative to the crisis.

The signers, however, say that the sweeping bill would only be an initial step, and that more legislation would be needed to deal with issues related to legal immigration and interior enforcement.

"Leadership should put additional, shovel-ready border security and immigration bills on the floor throughout the next Congress—from ending sanctuary policies to protecting American workers," they say. "Congress will also need to conduct aggressive oversight and properly control federal funding mechanisms."

"All of the undersigned groups and individuals are here to help," they stress.

Currently, Republicans struggle to get legislation passed in Congress due to the 50-50 split in the Senate and the Democratic majority in the House. But Republicans have been gearing up for a potential retake of both chambers in the midterms – where the overwhelming border crisis is a top issue for many voters.

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Congressional Republicans are currently pushing for a vote on bipartisan legislation to reverse the ending of Title 42 on May 23. Last month, more than 130 House Republicans expressed "grave concerns" about DHS Secretary Alejandro Mayorkas’ suitability for office and grilled him on his understanding of his role as DHS chief.

A senior House GOP aide told Fox News Digital that the letter shows that House Republicans are "focused on aggressive accountability and oversight of the Biden administration and of Secretary Mayorkas' failure at our southern border."