Employment Bill [Lords]

I understand the point that the Minister is making about trade unions and people who have been past members of an organisation that is incompatible with the aims and objectives of a trade union. However, as I understand the Bill, if someone had been a member of such an organisation in years past, that would prevent them from ever joining a trade union. I find that a little worrying. I do not know what the answer is, and I wonder whether the Minister has an idea.