House Democrats are accusing the Republican majority of censoring language in mailings to constituents about a Republican plan to privatize Medicare for future retirees.

At issue is official mail that goes to constituents with taxpayers picking up the cost of postage. Any materials mailed at taxpayer expense have to have bipartisan approval.

In a letter to House Speaker John Boehner, five Democrats complained that previously approved language describing the proposal by Republican Representative Paul Ryan no longer was okay.

“Given this abrupt and inconsistent new interpretation of the established Franking Guidelines, we must surmise that there is a deliberate, strategic attempt to censor any Member communication that echoes the widespread public criticism of the Republican Plan for Medicare,” the Democrats wrote.

“This politically motivated censorship undermines our ability to execute one of our primary roles and diminishes the credibility of this institution,” they added.