19. Deferred tax

The following are the major deferred tax liabilities and (assets) recognised by the Group and movements thereon during the current and prior reporting periods:

Accelerated tax depreciation
Tax losses
Retirement benefit obligations
At 1 January 2012 (as previously reported)39.5(4.4)(3.2)(4.7)27.2
Impact of IAS 19 (revised)(0.2)(0.2)
At 1 January 2012 (as restated)39.5(4.4)(3.4)(4.7)27.0
Charge / (credit) to income2.8(1.1)(0.7)(0.9)0.1
Credit to equity(1.4)(1.0)(2.4)
Acquisition of subsidiaries(0.2)(0.2)
Exchange differences(1.5)
Effect of change in tax rate:
Income statement(0.8)0.4(0.2)(0.6)
At 1 January 201339.9(5.7)(5.3)(6.0)22.9
Charge / (credit) to income1.62.1(0.1)2.66.2
Charge to equity0.10.30.4
Acquisition of subsidiaries1.02.33.3
Exchange differences(0.1)(0.1)(0.1)0.1(0.2)
Effect of change in tax rate:
Income statement(0.4)(0.4)
At 31 December 201341.8(3.7)(5.2)(0.7)32.2

The following is the analysis of the deferred tax balances for financial reporting purposes:

Deferred tax liabilities61.656.4
Deferred tax assets(29.4)(33.5)

Other deferred tax assets relate to provisions recognised in the financial statements that are not yet deductible for tax purposes, in particular in relation to restructuring charges, share-based payments and local profit differences that are expected to reverse over time.

At the balance sheet date, the Group has unused tax losses of £146.5m (2012: £122.3m) available for offset against future profits. A deferred tax asset has been recognised in respect of £12.9m (2012: £18.7m) of such losses, based on management forecasts of future taxable profits against which the assets can be recovered in the relevant jurisdictions. No deferred tax asset has been recognised in respect of the remaining £133.6m (2012: £103.6m) of such losses where there remains uncertainty over the timing of utilisation relating to future profitability. The majority of losses may be carried forward indefinitely.

A deferred tax liability of £0.4m (2012: £0.3m) relating to the temporary differences on unremitted earnings of overseas subsidiaries has not been recognised as the Group is able to control the timing of the reversal of these temporary differences and it is probable that they will not reverse in the foreseeable future. Temporary differences arising in connection with interests in associates and joint ventures are insignificant.