Mr Cameron , speaking at St Stephen 's Club in London , said that he had also dealt with a series of " smaller but nevertheless significant " matters involving George Osborne , the Shadow Chancellor , who is returning £ 400 claimed for a taxi journey , Ken Clarke , the Shadow Business Secretary , who pays back a £ 600 council tax discount , and David Willetts , the Shadow Skills Secretary , who returns £ 115 plus VAT for electrical repairs .