Barack Obama’s re-election campaign kept up pressure against Republican rival Mitt Romney on Friday, challenging the former Massachusetts governor to release at least five years of tax returns.

Obama campaign manager Jim Messina made the tax-disclosure challenge to Romney campaign manager Matt Rhoades in a letter Friday morning. Messina said he was taking the step because Romney “apparently fears the more he offers, the more our campaign will demand that he provide.”

Here’s the full text of the Obama letter to Romney [via CBS’ Mark Knoller]:

Dear Matt:

I am writing to ask again that the Governor release multiple years of tax returns, but also to make an offer that should address his concerns about the additional disclosures. Governor Romney apparently fears that the more he offers, the more our campaign will demand that he provide. So I am prepared to provide assurances on just that point: if the Governor will release five years of returns, I commit in turn that we will not criticize him for not releasing more — neither in ads nor in other public communications or commentary for the rest of the campaign.

This request for the release of five years, covering the complete returns for 2007-2012, is surely not unreasonable. Other Presidential candidates have released more, including the Governor’s father who provided 12 years of returns. In the Governor’s case, a five year release would appropriately span all the years that he has been a candidate for President. It would also help answer outstanding questions raised by the one return he has released to date, such as the range in the effective rates paid, the foreign accounts maintained, the foreign investments made, and the types of tax shelters used.

To provide these five years, the Governor would have to release only three more sets of returns in addition to the 2010 return he has released and the 2011 return he has pledged to provide. And, I repeat, the Governor and his campaign can expect in return that we will refrain from questioning whether he has released enough or pressing for more.

I look forward to your reply.

Jim Messina
Obama for America Campaign Manager

In other words, release more tax returns and we’ll stop criticizing you for not releasing more (and more) tax returns. Notice there’s no commitment not to criticize what’s in the tax returns.

The Romney camp fired back quickly. Here’s the full text of their response [again, via Knoller]:

Hey Jim,

Thanks for the note.

It is clear that President Obama wants nothing more than to talk about Governor Romney’s tax returns instead of the issues that matter to voters, like putting Americans back to work, fixing the economy and reining in spending.

If Governor Romney’s tax returns are the core message of your campaign, there will be ample time for President Obama to discuss them over the next 81 days.

In the meantime, Governor Romney will continue to lay out his plans for a stronger middle class, to save Medicare, to put work back into welfare, and help the 23 million Americans struggling to find work in the Obama economy.

See you in Denver.

Thanks,

Matt Rhoades
Romney for President
Campaign Manager

Romney, as some of you may already know, made headlines yesterday when he told reporters he’s never paid less than 13 percent of his income in taxes during the past decade. The presumed Republican presidential candidate said he has also given generously to charity and that, including those contributions, he’s given up more than 20 percent of his income annually.

Aides later said Romney meant to say 13.9 percent, the amount he already disclosed for his 2010 federal return.

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The Associated Press contributed to this report. Front page photo source via AP.