WASHINGTON DC: Several Democratic members of the House of Representatives Friday said calls from Barack Obama helped convince them to switch their votes and back a US$700bn Wall Street bailout.

Maryland Democratic representatives Donna Edwards and Elijah Cummings said they had both received calls from the party's White House nominee, after voting against the original package which the House rejected on Monday.

"It meant a lot to me that somebody who at least has a 50-50 shot at being the next President of the United States would take time," Cummings said.

Obama said during the call that he would push attempts to reform bankruptcy laws to help ill-fated homeowners escape foreclosure, Cummings said, but stressed urgent action to save the US financial system was vital.

"We will work on this, but right now we have got to straighten this out," Cummings quoted Obama as saying.

Edwards said Obama reached out to her on Thursday morning, as she was considering how she would come down in Friday's looming vote.

"I had a very good conversation with Senator Obama yesterday morning, and I had to weigh on that the entire day in coming to this decision," Edwards said.

Both lawmakers said they had to balance the fact that they believed that the bill lacked sufficient measures to attack the foreclosure crisis with the fact that some constituents were struggling amid a deepening credit crunch.

Cummings and Edwards are both members of the Congressional Black Caucus (CBC) a majority of which voted against the bill on Monday. Sources said that Obama also placed other calls to members of the key Democratic voting block.

Another prominent African American lawmaker John Lewis, a prominent Obama supporter, also said Friday he would switch his vote.

"I have decided that the cost of doing nothing is greater than the cost of doing something," Lewis said.

"The fear that is gripping Wall Street has the power to shut down Main Street," he said.

"We cannot and we must not allow this to happen. The people are afraid. their retirement savings are slipping away."

A fourth member of the CBC, Representative Barbara Lee of California also publicly switched her vote, and quoted Obama's speech on the Senate floor on Wednesday, in which he argued that inaction would be disastrous. (AFP)