The week before last, Thomas Fazi and I had a response to a recent British attack on Modern Monetary Theory (MMT) published in The Tribune magazine (June 5, 2019) – For MMT. In effect, there were two quite separate topics that needed to be discussed: (a) the misrepresentation of MMT; and (b) the issues pertaining to British Labour Party policy proposals. The article we were responding to – Against MMT – written by a former Labour Party advisor, was not really about MMT at all, as you will see. Instead, it appeared to be an attempt to defend a policy approach, that I have previously criticised as giving to much back to the neoliberals. Whenever, progressives use neoliberal frames, language or concepts, it turns out badly for them. Anyway, the published article only allowed 3,000 words, which made it difficult to cover the two topics in any depth. In this three-part series, you can read a longer version of our reply to the ‘Against MMT’ article, and, criticisms from the elements on the Left, generally, who think it is a smart tactic to talk like neoliberals and express fear of global capital markets. In this final Part, we focus explicitly on Labour Party’s Fiscal Credibility Rule – which uses these neoliberal frames – and we show that it would fail in a deep recession, causing grief to a Labour government should it be in office at that time.