The Group also has a number of embedded foreign exchange derivatives in host Commercial revenue contracts. These are separately recognised in the financial statements at fair value since they are not closely related to the host contract. As of 30 June 2014 the fair value of such derivatives was a net liability of £1,320,000 (2013: £nil).
Interest rate risk The Group has no significant interest bearing assets other than cash on deposit which attracts interest at a small margin above UK base rates. The Group's interest rate risk arises from its borrowings. Borrowings issued at variable interest rates expose the Group to cash flow interest rate risk. Borrowings issued at fixed rates expose the Group to fair value interest rate risk. The Group's borrowings are denominated in pounds sterling and US dollar.
Full details of the Group's borrowings and associated interest rates can be found in note 23.
The Group manages its cash flow interest rate risk where appropriate using interest rate swaps at contract lengths consistent with the repayment schedule of the borrowings. Such interest rate swaps have the economic effect of converting borrowings from floating rates to fixed rates. Consequently, the impact on equity and post-tax profit of a 1.0% shift in interest rates would not be material to any periods presented. The Group has entered into a number of swap agreements. The following table details the interest rate swaps committed to at the reporting date: