In March 2012, Streeter was one of three MPs who signed a letter to the Advertising Standards Authority asking it to reverse its decision to stop the Christian group "Healing on the Streets of Bath" from making explicit claims that prayer can heal. The letter called for the ASA to provide "indisputable scientific evidence" that faith healing did not work. Another signer, Tim Farron of the Liberal Democrats later wrote that the letter was not "well-worded" and that he should not have signed it "as it was written".