I am advised by the Revenue Commissioners that the numbers of claimants for mortgage interest relief by way of tax relief at source for 2006, the most recent year for which full actual figures are available, is 593,200. While corresponding figures for 2007 will not be available until all annual returns for that year are received from the institutions which operate the tax relief at source system, it is estimated that the numbers of claimants for 2007 is of the order of 652,000. This figure is provisional and subject to revision. It should be noted that married couples are counted as a single claimant.