While it's important to get legal advice, there are two things to bear in mind.
First, the meaning of a law can only be settled in the courts, strictly speaking. A legal opinion is a best effort, but it is an opinion, not a judgement.
Second, Parliament can amend any law it passes at will. And it has the power -- rarely but sometimes exercised -- to make its legislation retroactively effective.
First, the meaning of a law can only be settled in the courts, strictly speaking. A legal opinion is a best effort, but it is an opinion, not a judgement.
Second, Parliament can amend any law it passes at will. And it has the power -- rarely but sometimes exercised -- to make its legislation retroactively effective.