Hardly Trevelyan's policies Thompson he was after all only a civil servant appointed as assistant secretary to HM Treasury. I do not think that they MAKE policy, that is the sole responsibility of the Government of the day. In the case of Trevelyan those would have been the policies of Peel's Tory Government which were replaced by Russell's Whig/Liberal Government.

I do not believe that any songs of the time mention Trevelyan.