Mr Grayling took aim yesterday at the Institute of Public Policy Research (North) which claimed spending per head was vastly higher in the South.
But Ed Cox, IPPR North’s director, said the Government’s own figures showed if the North had received the same funding as London over the past 10 years, the region would have received £10bn more.
He added: “He’s wrong. He’s actually wrong about historical spending. If there is so much discussion around this, we would be happy for this matter to be referred to the Office for National Statistics.”