25U.K.The operation of section 279(1) of the Taxes Act 1988 for a year of assessment earlier than the year 1990-91 in the case of a married woman shall not affect the question whether there is any income of hers chargeable to income tax for the year 1990-91 or any subsequent year of assessment or, if there is, what is to be taken to be its amount for income tax purposes.