i'll take a wise guess here that you don't know the structure and the arguments because you haven't done your research yet. you really have to do that first - read some articles. what are the issues with delegated legislation(?). who says it threatens parliamentary sovereignty and rule of law and do you agree with them? who says it doesn't threaten because there are controls(?). have you written an essay at uni yet? there isn't a magic number as to how many arguments you make. you just have to explore the issues, create an argument for why you agree/disagree with the statement in the question, explore the counter argument and plug any potential holes in your argument. in this case you'd potentially have threatening, non-threatening, potentially threatening, conclusion.