As Guido reported in his Sun column yesterday – and the Sunday Mirror “exclusively” revealed on page 2 – Dave has been on a secret no photo-op visit to a food bank. The PM was regularly coming under heavy fire for claiming the six-fold rise in food banks across the country was a sign of the Big Society in action and eventually promised to pop down to one. Last week he wrote to Luciana Berger, telling her he had “visited a local food bank on 9 February 2013”. For some reason he forgot to invite the usual camera crew along…