Four influential Senate Republicans have sent a letter to colleagues voicing strong opposition to comprehensive immigration legislation headed to the Senate floor, warning it will not secure the nation’s borders.

Sens. Ted Cruz (Texas), Chuck Grassley (Iowa), Jeff Sessions (Ala.) and Mike Lee (Utah) said in a June 4 letter the immigration bill repeats the mistakes of the 1986 immigration reform law.

“In 1986, the American people were promised that, in exchange for granting legal status to illegal immigrants, the border would be secured and the law enforced. Washington broke these promises,” they wrote. “Unfortunately, the so-called ‘Gang of Eight’ immigration bill, S. 744, repeats these mistakes.”