Random drug tests for all politicians.

I want to discover the revealed preference of the people who have control over the laws that have filled the prisons over capacity with people convicted of drug offences. This should extend to the entire Judiciary of England and Wales. I cannot see any reasonable argument against this, therefore the subject should be discussed in Parliament to see exactly who objects to this and why. Spending isn't an issue, as we've seen with covid that they're willing to print money as if it grows on trees.