House Republicans will call up legislation to the floor next week aimed at blocking the Internal Revenue Service from asking about or learning the identity of people who contribute money to nonprofit groups.

The "Preventing IRS Abuse and Protecting free Speech Act" will get a vote following the revelation that the IRS in 2012 leaked to the media the identities of donors to the National Organization for Marriage. The list included then-GOP presidential nominee Mitt Romney.

The bill, sponsored by Rep. Peter Roskam, R-Ill., would prohibit the IRS from requesting the identity of contributors to 501(c) organizations as part of the groups' annual returns.

Republicans say the bill is needed to stop an IRS pattern of targeting conservative groups. A Treasury Department watchdog found conservative and Tea Party groups were singled out for additional scrutiny when they applied for tax-exempt status prior to the 2012 election, and the Romney leak, they say, showed that nothing can stop the IRS from making inappropriate political decisions when it wants.

"As we have seen over the last several years, the IRS has exploited sensitive taxpayer information to penalize tax-exempt organizations that do not align with certain political beliefs," said House Ways and Means Committee Chairman Kevin Brady, R-Texas. "By eliminating invasive reporting requirements in current law, this legislation will protect taxpayers' identities and prevent the IRS from improperly targeting particular organizations."

The legislation passed the tax-writing panel on April 28th along party lines. Democrats say the bill is a GOP move to keep their big donors a secret.

"What this bill does, to put it simply, is to solidify the secrecy around the role of big money in campaigns," said Ways and Means ranking member Sander Levin, D-Mich.