WASHINGTON (Reuters) - In a rare Saturday session, the U.S. Senate voted against moving forward with legislation that would boost funding for a federal program that helps low- income families pay their cooling and heating bills.

The legislation would nearly double money for the Low Income Home Energy Assistance Program, commonly known as LIHEAP, to $5.1 billion.

“At a time when the cost of home heating fuels and electricity are soaring, and when the economy is in a decline, millions of Americans are finding it harder and harder to stay warm in the winter or cool in the summer,” said independent Sen. Bernie Sanders of Vermont, who sponsored the legislation.

Low-income families spend on average about 15 percent of their income on home energy bills, compared with 3.4 percent for all other households.

Senators voted 50-35 to limit debate on the bill, but fell short of the 60 votes needed to move to final passage.

The White House threatened to veto the bill on grounds LIHEAP operates mostly in the winter and the heating season is over. It said a contingency fund held $100 million to cover emergencies through the September 30 end of the fiscal year.