The U.S. Senate has blocked debate on the so-called "Buffet Rule" proposed by President Barack Obama that would raise the minimum income tax on millionaires to 30 percent.

The Senate vote on Monday was nine shy of 60 to open debate on the tax plan, with 51 senators in favor of the tax and 45 opposed.

Republican floor leader Mitch McConnell accused Obama of seeking to mislead the public, while Democratic Senator Charles Schumer claimed that rich people should be making a greater sacrifice.

Preceding the procedural vote, Obama called on Republican politicians to support the Buffett Rule, explaining that two thirds of rich people and nearly half of Republicans are in favor of his tax plan.