In the news

So the system worked like this.

As an MP, you could get assistance for mortgage interest payments on a second home near Westminster. It was an allowable expense.

The MP would foot the bill for the deposit and any repayments - It's possible they were arranging interest only finance.

They would then claim the interest which could be sizeable - up to £24K was claimable IIRC.

That said, renting a property would cost the taxpayer more.

Because the property was bought, not rented, and was their second home, when they sold it they paid capital gains and the treasury got their money back.

The problem was that the MP made money out of it too, because house prices were rising. But that's kind-of not terrible because they bought the property in the first place and shouldered the risk. For the treasury to get their money back the property would need to be sold at a profit.

The mistake was allowing them to claim on property they bought - the system has now changed and they can only claim on property they rent. But that means the treasury doesn't get their money back. And rich MPs can still get richer through property in London.

It's all a bit hate the game not the player.