(CNN) - Sarah Palin is taking aim at White House Chief of Staff Rahm Emanuel, characterizing the top Obama aide as an irresponsible liar.
"Rahm, u lie," Palin wrote on Twitter Sunday after Emanuel said on ABC's This Week that Republican Rep. Joe Barton's controversial apology to BP last week exposed the political philosophy of the Republican Party.
"That's not a political gaffe, those are prepared remarks," said Emanuel. "That is a philosophy."
"RahmEmanuel= as shallow/narrowminded/political/irresponsible as they come,to falsely claim Barton's BP comment is "GOP philosophy," Palin also tweeted in reply to Emanuel's comments.
The White House has not responded to Palin's comments.
At a House committee hearing Thursday intended to grill BP CEO Tony Hayward, Barton instead drew the headlines for an opening statement that apologized to BP over the $20 billion account to pay damage claims that the company created at the request of President Barack Obama.
Barton's statement – which was quickly retracted under pressure from House GOP leadership – provided Democrats an opportunity to deflect growing public disenchantment with how the government was responding to the oil disaster.
Acknowledging the political gift handed to his party by Barton, Emanuel also said on ABC that Barton's comment and other pro-BP statements by Republicans including Kentucky Senate candidate Rand Paul would be a factor in the November congressional elections.
"In case you forgot what Republican governance is like, Joe Barton reminded you," Emanuel said, adding the GOP considers BP the "aggrieved party" instead of the oil giant responsible for the worst environmental disaster in U.S. history.
However, a statement later Sunday from the House Energy and Commerce Committee Republicans said Barton spoke off the cuff. The statement included what it said were his prepared remarks, which made no mention of an apology to BP or criticism of the fund the company created to pay for damages from the oil
Republican Sen. Lisa Murkowski of oil-rich Alaska also challenged Emanuel's comments, telling the CNN program "State of the Union" that the White House chief of staff was wrong.
UPDATE: White House spokesman Bill Burton responded to Palin's tweet Monday in the daily briefing with reporters.
"As a leader of the Republican Party, people would be interested in knowing whether or not she thinks that, as Congressman Barton said, that $20 billion set aside in a fund to pay the claims of people who have been harmed by the BP oil spill was a shakedown. I don't think that the American people think that," Burton said.