As an editor he was an early advocate for tariff protection which later he brought to prominence when he was editor of "The Age" under the proprietorship of David Syme. But his rise ceased abruptly in 1854 after a controversial libel suit was brought against him by the Crown Prosecutor George Mackay whose evident drunkenness on duty Harrison had editorially deplored. The jury brought in a verdict for Mackay with Harrison to pay £800 damages. In 1862, although his assets were worth £22,000, he had to sell the "Advertiser" to escape bankruptcy.