PensionsContributions to defined contribution plans are expensed in the period to which they relate.Leased assetsA lease is classified as a finance lease if it transfers substantially all the risks and rewards incidental to ownership. All other leases are classified as operating leases. The rights of use and obligations under finance leases are initially recognised as assets and liabilities at amounts equal to the fair value of the leased assets or, if lower, the present value of the minimum lease payments. Minimum lease payments are apportioned between the finance charge and the reduction in the outstanding liability using the effective interest rate method. The finance charge is allocated to each period during the lease so as to produce a constant periodic rate of interest on the remaining balance of the liability. Leased assets are depreciated in accordance with the company's policy for tangible fixed assets. If there is no reasonable certainty that ownership will be obtained at the end of the lease term, the asset is depreciated over the lower of the lease term and its useful life. Operating lease payments are recognised as an expense on a straight line basis over the lease term.TaxationA current tax liability is recognised for the tax payable on the taxable profit of the current and past periods. A current tax asset is recognised in respect of a tax loss that can be carried back to recover tax paid in a previous period. Deferred tax is recognised in respect of all timing differences between the recognition of income and expenses in the financial statements and their inclusion in tax assessments. Unrelieved tax losses and other deferred tax assets are recognised only to the extent that it is probable that they will be recovered against the reversal of deferred tax liabilities or other future taxable profits. Deferred tax is measured using the tax rates and laws that have been enacted or substantively enacted by the reporting date and that are expected to apply to the reversal of the timing difference, except for revalued land and investment property where the tax rate that applies to the sale of the asset is used. Current and deferred tax assets and liabilities are not discounted.