The U.S. Senate began a vote-a-rama session Thursday as lawmakers moved toward passing a budget reconciliation package focused on funding immigration enforcement agencies under the Department of Homeland Security.

The voting marathon follows a party-line procedural vote that kicked off hours of debate on the legislation. The process allows for unlimited back-to-back amendment votes before final passage, which is expected later this week.

Republican senators are seeking to advance the immigration funding package without Democratic support, utilizing the reconciliation process that requires only a simple majority for passage. The legislation includes funding for Immigration and Customs Enforcement and other border security agencies.

The package reportedly totals approximately $70 billion for immigration-related enforcement. However, the legislation faces uncertainty as senators propose various amendments during the voting process.

Among the provisions drawing attention is a $2 billion fund that has become a target for amendments from both parties. The fund's specific purpose and implementation details remain subjects of debate as the voting continues.

The vote-a-rama format typically involves extended sessions where senators can propose unlimited amendments, often lasting through the night until final passage is achieved.