Mortgage interest relief at source
Mortgage interest relief at source, or MIRAS, was a scheme introduced in the United Kingdom by Chancellor of the Exchequer Roy Jenkins in 1969  in a bid to encourage home ownership; it allowed borrowers tax relief for interest payments on their mortgage.
In the 1983 Budget Geoffrey Howe raised the tax allowance from £25,000 to £30,000. Unmarried couples with joint mortgages could pool their allowances to £60,000, a provision known as Multiple Mortgage Tax Relief. This remained in place until the 1988 Budget, when Nigel Lawson ended the option to pool allowances from August 1988. Lawson later publicly expressed regret at not having implemented the change with effect from the time of the budget, as it is generally accepted that the rush to beat the deadline fuelled a sharp increase in house prices.