U.S. Sen. Scott Brown demanded challenger Elizabeth Warren cough up nearly $300,000 to reimburse taxpayers for a push undertaken by her daughter’s liberal think tank to register welfare recipients to vote.

”It’s been disturbing for a lot of people to learn that the state’s welfare department undertook an unprecedented voter registration drive at the behest of Elizabeth Warren’s daughter and the organization she represents,” wrote Brown in a statement. “It is clear that this was done to aid Elizabeth Warren’s Senate campaign. Professor Warren has more than $13 million dollars in her campaign account, and if she wants to mail every welfare recipient a voter registration form, she should do so at her own expense, not taxpayers’. She should immediately reimburse the state for the cost of this mailing and stop playing politics with the taxpayers’ money.”

The Herald reported this week that Demos, a liberal organization whose board is chaired by Warren’s daughter, Amelia Warren Tyagi, pioneered a legal effort to ensure the Bay State’s welfare department offered recipients the opportunity to register to vote.