(CNN) - Hillary Clinton and Barack Obama’s campaigns each accused the other of plagiarizing portions of their campaign speeches Monday, with the Clinton campaign accusing Obama of borrowing from a close supporter - and the Illinois senator’s campaign accusing his rival of lifting from Obama himself.
On a conference call with reporters, Clinton spokesman Howard Wolfson said it was clear Obama had “lifted rhetoric” from Massachusetts Gov. Deval Patrick. Portions of Patrick’s speeches during his gubernatorial run resemble some of Obama’s addresses this year.
“If you’re going to be talking about the value of words, the words ought to be your own,” said Wolfson.
In a statement this morning, Patrick said the two men often shared ideas and language with each other.
As Wolfson spoke, the Obama campaign hosted a competing conference call, during which campaign manager David Plouffe said Clinton was "denigrating the power of words."
The Obama camp also said Clinton had a pattern of borrowing some of the Illinois senator’s signature phrases, including “Yes, We Can” and “Fired Up, Ready to Go.”
They also circulated a YouTube video and list of these alleged instances to reporters still listening to Wolfson.
"...We have seen thousands and thousands of Iowans over the last week and we are fired up and we are ready to go because we know America is ready for change and the process starts right here in Iowa," says Clinton in the pre-Iowa caucuses clip circulated by the Obama campaign Monday.
UPDATE (1:45 p.m. ET): CNN's Chris Welch reports that Obama is playing down the allegations, telling reporters that he's written two books and most of his own speeches.
“Deval and I do trade ideas all the time, and you know he's occasionally used lines of mine, and I at a Jefferson Jackson dinner in Wisconsin used some words of his. And you know I would add I’ve noticed on occasion Sen. Clinton has used words of mine as well,” said Obama, adding, "...As I said before, I really don't think this is too big of a deal."
–CNN Associate Political Editor Rebecca Sinderbrand