(CBS News) DENVER - Mitt Romney fired back on Thursday against Democrats questioning his tax proposals and tax-paying history, rebuking President Obama over his characterization of Romney's tax plan and Senate Majority Leader Harry Reid over his claim that the presumptive GOP nominee has not paid income taxes in 10 years.
Romney was campaigning in Colorado on Thursday touting his own tax plan at the same time that the Obama campaign spent the day highlighting a Tax Policy Center study released this week. The nonpartisan center concluded Romney's plan would result in a net tax increase for lower- and middle-income taxpayers in order to cut taxes for the highest earners.
"He knows that is a completely dishonest characterization of my plan," said Romney, whose campaign has characterized the study as a "joke" because it was co-authored by a former Obama advisor - even though the Tax Policy Center's director, Donald Marron, worked in George W. Bush's White House and the Romney campaign has praised the center's work in the past.
Speaking in an interview on the radio program of conservative Fox News host Sean Hannity, Romney said his plan ensures that the wealthiest Americans continue to pay the same share of taxes, and that the president was merely seeking to distract from his own stewardship of the economy.
"He has a way of putting out a false statement and then attacking it and making it sound like it's mine which of course it's not. He knows better than that. It really is a matter of a president doing almost anything to try and avoid talking about his own record," he said in the interview.
Obama wasn't the only Democrat whom Romney accused of misconstruing the facts. He made a similar claim of Reid, who has told reporters multiple times this week that he has sources -- whom he has declined to name -- saying Romney hasn't paid taxes in 10 years.
(Related: Romney grades Obama on "accountability" report card.)
Romney dismissed it as little more than "baloney."
"It's time for Harry to put up or shut up," Romney said. "Harry's gonna have to describe who he spoke with, because of course that's totally and completely wrong. It's untrue, dishonest and inaccurate. It's wrong. So I'm looking forward to having Harry reveal his sources, and we'll probably find out it's the White House."
Reid has said the burden of proof is on Romney, who has steadfastly refused to release more than two years of his tax returns.
The candidate declined yet another opportunity to make an announcement about his vice presidential pick or thetiming, but praised the "large number of people" from which he's had to pick. He will meet with several of those options - various Republican governors - during an event in Aspen on Thursday evening.