1: British parliamentary Format
3: PRIME MINISTER Needs to define the case that proposition is putting forward, and give a mechanism if the motion requires one. E. g. if the motion is "This house supports nationalism" you need to define what you mean by nationalism. If the motion is "This house would institute a voting test" you need to define things like what this test would be, who would set it, etc. Should outline the main arguments for the motion. Can be useful to talk about what problem it is the motion is trying to fix. Can talk about core principles of the case. Allows you to frame the debate, what will be argued about and in what context.
4: Leader of the opposition Similar to the PM but without the requirement to do definitions and mechanism. But it is still tactically useful to outline what your sides case is. (e. g. do you agree with the general aim of the prop but disagree with how they are doing it, or not) Should directly rebut the prime minister and lay out the main points of the opposition case.
5: DEPUTY PRIME MINISTER/DEPUTY LEADER OF OPPOSITION Should both rebut previous speakers. Do any repair work and elaboration that needs done on their partners arguments (particularly stuff that has been rebutted by the other side) And/or add entirely new arguments.
6: Member of GOVERNMENT/MEMBER OF OPPOSITION Both of these speakers do what is called an extension speech. This means they should add something substantially new to the debate. This can either involve bringing in an entirely new argument, area, topic, idea, framing. Or adding substantial extra detail to an argument that has already been brought up (often called an "analysis" extension). For example, in a debate on immigration, if the top half teams talked exclusively about about economic migration the extension could talk about refugees, or if they had stated that immigration is good/bad for the economy but not analysed it well, the extension could be explaining why this is the case in more detail. Tactically it is useful to make it very clear to the judges what your new contribution is. Should also rebut previous speakers. Member of opposition in particular needs to rebut the prop extension.
7: Government whip/opposition whip Both of these speakers do what is called a summation speech. Their job is not to introduce new material but to summarise what has been said and show that their sides material was stronger. This should not just be a list of who said what, but should be more like a an editorialised description of what happened. This is a good time to do comparative and show that your arguments were more important/impactful/better analysed. It is tactically often a good idea to put extra emphasis on your partners extension material. With the exception of rebuttal should not add any new material to the debate. Rebuttal is particularly important for the Government Whip as they are the only one who gets a chance to reply to the opp extension.