FIRST ON FOX: A coalition of conservative immigration groups is calling for the inclusion of the Republican border security and asylum overhaul in a stop-gap funding bill to avoid a possible government shutdown at the end of the month -- calling it a "singular opportunity" to tackle the migrant crisis.

The groups, led by the Heritage Foundation, call for the Secure the Border Act (H.R. 2) -- which passed the chamber earlier this year -- to be included in a continuing resolution to keep the government funded past Sept. 30.

"If H.R. 2 is attached to the CR, as it should be, then the Biden Administration must choose: shut down the border crisis and fund the government or shut down the government in order to maintain the border crisis," the groups say in a letter to congressional leaders, obtained by Fox News Digital. 

CRUZ LEADS SENATE PUSH FOR HOUSE-PASSED BILL TO OVERHAUL BORDER SECURITY, TACKLE MIGRANT CRISIS 

Tucson Sector

Conservative groups want Congress to include a border security bill in the continuing resolution. (John Moore/Getty Images)

The Groups on the letter include the America First Policy Institute, Numbers USA, the Federation for American Immigration Reform (FAIR), the Eagle Forum and the Texas Public Policy Foundation. It includes the signatures of former Trump DHS officials including former acting acting ICE Director Tom Homan, former acting CBP Commissioner Mark Morgan and former Border Patrol Chief Rodney Scott.

The bill, which is also being introduced in the Senate on Thursday, would see sweeping changes to the border security and asylum processing system. It would restart border wall construction, drastically limit the use of parole to release migrans, increase DNA and biometrics collection and expand the number of Border Patrol agents.

Separately, it would reinstate the Trump-era Remain-in-Mexico program, block the use of the CBP One app for migration, remove funding to NGOs facilitating transporting and housing for migrants -- and mandate an E-Verify work authorization program.

Funding HR2 Coalition Letter by Fox News on Scribd

The conservative groups say that not including the legislation in the continuing resolution "would result in the continuation of funding and policies put in place by the disastrous FY2023 omnibus, which has given the Biden Administration the ability to ‘manage’ a never-ending, self-inflicted crisis by allowing them to entice, guide, process, transport, house, and provide social services to even more illegal aliens."

The letter warns that Americans will have an "indisputable account" of where lawmakers stand on border security when it "gives a clear chance to finally end the crisis."  

BORDER PATROL SET ‘BOOKOUT’ TARGETS TO BRING MIGRANT CUSTODY NUMBERS TO ‘MANAGEABLE' LEVELS AMID NEW SURGE 

"It is your duty to use any means necessary to address the Biden administration’s open-borders agenda that not only undermines the rule of law, but threatens national sovereignty, economic security, and public safety daily. Congress cannot simply continue to fund the flood of illegal aliens this administration is ushering into America every day," they say.

They also add that, given their past advocacy on the issues in Congress, "we will be right there with you, urging all elected members to do their job at this moment to secure the border when this singular opportunity is presented."

A group of migrants who have crossed into the US from Mexico in Eagle Pass, Texas listen to instructions given by a Border Patrol Agent on August 25, 2023.

A group of migrants who have crossed into the US from Mexico in Eagle Pass, Texas listen to instructions given by a Border Patrol Agent on August 25, 2023. ((Photo by SUZANNE CORDEIRO / AFP) (P)

CLICK HERE TO GET THE FOX NEWS APP

The push comes as numbers are surging again at the border. Multiple sectors are overcapacity, with at least one resorting to street releases of migrants. Sources told Fox News on Thursday that early indications show migrant encounters for August on track to exceed 230,000, making it the 6th month this fiscal year over 200,000.

Fox News’ Griff Jenkins contributed to this report.