Impairment reviewThe viability of any project undertaken is reviewed on an ongoing basis. The carrying amount of the company's assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If there is evidence of impairment, the recoverable amount of the asset, (being the higher of the fair value less costs to sell and the value in use of the asset), is estimated to determine the extent of any such impairment.Finance costsFinance costs consist of interest payable on borrowings calculated using the effective interest rate method. Borrowing costs relating to the acquisition or construction of a qualifying asset are capitalised at the appropriate rate by adding them to the costs of qualifying assets being acquired or constructed. Borrowing costs that are not directly attributable to the acquisition or construction of a qualifying asset are recognised in the profit and loss account using the effective interest method.Financial assetsInvestments held as fixed assets are stated at cost less provision for any permanent diminution in value. Income from other investments together with any related tax credit is recognised in the profit and loss account in the year in which it is receivable.Trade and other receivablesTrade and other receivables are initially recognised at fair value and thereafter stated at amortised cost using the effective interest method less impairment losses for bad and doubtful debts except where the effect of discounting would be immaterial. In such cases the receivables are stated at cost less impairment losses for bad and doubtful debts.Borrowing costsBorrowing costs relating to the acquisition of assets are capitalised at the appropriate rate by adding them to the cost of assets being acquired. Investment income earned on the temporary investment of specific borrowings pending their expenditure on the assets is deducted from the borrowing costs eligible for capitalisation. All other borrowing costs are recognised in profit or loss in the period in which they are incurred.Trade and other payablesTrade and other payables are initially recognised at fair value and thereafter stated at amortised cost using the effective interest rate method, unless the effect of discounting would be immaterial, in which case they are stated at cost.Taxation and deferred taxationCurrent tax represents the amount expected to be paid or recovered in respect of taxable profits for the year and is calculated using the tax rates and laws that have been enacted or substantially enacted at the Statement of Financial Position date.Deferred tax is recognised in respect of all timing differences that have originated but not reversed at the balance sheet date where transactions or events have occurred at that date that will result in an obligation to pay more tax in the future, or a right to pay less tax in the future. Timing differences are temporary differences between the company's taxable profits and its results as stated in the financial statements.Deferred tax is measured on an undiscounted basis at the tax rates that are anticipated to apply in the periods in which the timing differences are expected to reverse, based on tax rates and laws that have been enacted or substantively enacted by the balance sheet date.Foreign currenciesMonetary assets and liabilities denominated in foreign currencies are translated at the rates of exchange ruling at the Statement of Financial Position date. Non-monetary items that are measured in terms of historical cost in a foreign currency are translated at the rates of exchange ruling at the date of the transaction. Non-monetary items that are measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined. The resulting exchange differences are dealt with in the Income Statement.