A fierce internal battle between Democrats shook the timetable for the adoption of the two giant investment plans by the US Congress.

The plans were part of Joe Biden’s infrastructure and social spending bill, amounting to nearly 5000 billion dollars.

Members of the Democratic-majority House of Representatives returned to Washington on Monday for several procedural votes. While the voting procedures are crucial to allowing Democrats to move toward the final passage of Biden's two plans by Congress, they are not expected to occur before the fall.

Democratic leaders had hoped to finalize the vote without any hitch in the House of Representatives by Tuesday evening. However, tensions between the left and center wings within the Democratic Party have emerged in recent days.

The crux of the issue is a dispute over which project should be prioritized on the voting schedule.

The Senate approved Biden's $1,200 billion infrastructure investment plan on August 10, with many Republicans backing it surprisingly.

In contrast, Democratic House Speaker Nancy Pelosi promised the left-wing caucus that she would first vote on the social component of Biden's plan, one of "massive investments of $3,500 billion in education, health, labor market, and climate."

Pelosi sees this as the only way to ensure the two plans pass in the House of Representatives, where she has only a narrow majority, as 100 progressives are calling for a vote on social spending first.

Progressives fear that centrists would relinquish support of the $3,500 billion social spending plan, considering it too huge if the infrastructure plan is voted first.

Each camp held its position on Monday morning, but discussions were intense to resolve the situation.

Biden, facing a difficult situation due to the chaotic withdrawal from Afghanistan, is expected to weigh in through backstage discussions.

A first procedural vote is scheduled for Monday evening in the House of Representatives to determine the rules that will frame the upcoming debates and votes on these two major bills.

A second, more important vote is expected Tuesday on the budget resolution, which should then allow Democrats to adopt the $3,500 billion plan with their votes in the Senate.