The U.S. House of Representatives is to vote Thursday on a plan by Republican House Speaker John Boehner to raise the debt ceiling and cut spending.

Boehner's plan has attracted criticism from the ultra-conservative Tea Party faction of the Republican party, and opposition from Democrats. Conservatives say it cuts too little spending, Democrats complain Boehner's plan would bring the issue back again before the next election.

Even if Boehner's plan passes the Republican-controlled House of Representatives, it faces obstacles in the Democratic-controlled Senate.

Without an agreement to raise the $14.3 trillion legal limit on borrowing by August 2, the U.S. Treasury Department says it will not have enough money to pay all its bills. That could bring a default, that would likely prompt rating agencies to cut the credit rating of the United States, bringing higher interest rates and hurting economic growth.

The current impasse worries investors, and many stock markets have fallen in recent days.

But a compromise might emerge as Congressional leaders discuss Boehner's plan and a rival Democratic version by Senate Majority Leader Harry Reid. Reid's plan no longer calls for a tax increase on the wealthy, which is strongly opposed by Republicans.

White House press secretary Jay Carney says it is clear that a successful compromise would significantly cut spending, set up a way to tax reform and entitlement spending in the future, and lift the debt ceiling through next year.