Washington, United States: US Senate Democrats on Tuesday blocked committee votes on two of Donald Trump's nominations for key posts, heightening tensions over the new president's cabinet picks as he blasts the opposition party for obstruction.

"Today Senate Finance Democrats refused to move forward with nominations of Mnuchin & Price," Senator Ron Wyden, top Democrat on the finance committee, said on Twitter, referring to Treasury secretary nominee Steven Mnuchin and Tom Price, Trump's pick for health secretary.

Democrats, alarmed by what they see as extreme picks for a raft of key posts and angered by Trump's aggressive first week in office, appear to have dug in their heels.

"The litany of ethics revelations regarding Tom Price are strong evidence that he cannot be allowed to have control of Medicare," Wyden said. 

He was referring to contentious accusations by Democrats that Price invested in a medical company that would have benefited from legislation that Price, a congressman from Georgia, co-sponsored.

"Mr. Mnuchin continued to fail to come clean on shady foreclosure practices that hurt Americans," Wyden added.

Mnuchin, a Wall Street banker and Hollywood financier, was accused during his confirmation hearing of failing to disclose offshore holdings, and grilled over the home mortgage foreclosure practices of a bank he owned.

Senate Finance Committee chairman Orrin Hatch was visibly furious as he sat in a hearing with no Democrats.

"It's a sad time when this bipartisan committee has become a prop in a partisan sideshow," he fumed. 

"I think they ought to stop posturing and acting like idiots."

Senate rules require at least one lawmaker from the opposition party to be present for votes to be held. 

Democrats told Hatch they wanted more time to demand new information from the nominees.

"I do not want to hear from any of them about 'doing our jobs,'" Hatch said. "We're here. They are not."

Trump has repeatedly assailed Democrats for slow-walking nominations for political reasons.

"When will the Democrats give us our attorney general and rest of Cabinet! They should be ashamed of themselves!" Trump tweeted early Tuesday.

The Senate was holding a flurry of votes Tuesday, including a confirmation vote on the Senate floor for Elaine Chao as secretary of transportation.

Attorney General nominee Jeff Sessions was to get his vote in the Senate Judiciary Committee, after Democrats on the panel delayed the vote by a week.

Also receiving votes before relevant Senate panels are nominees for energy secretary, Rick Perry; interior secretary, Ryan Zinke; and education secretary, Betsy DeVos.