Law vs Law and PoliticsWatch
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Regardless of whether you choose law or law with politics, you will (almost definitely) receive a qualifying law degree. This means both options will allow you to become a solicitor or barrister with the requisite additional training so long as you select the core law modules necessary to achieve a qualifying law degree.
There are many people who are solicitors and barristers who did not, in fact, do a law degree: you will not be at any disadvantage if you choose law with politics over straight law. In fact, you should choose whatever you think will interest you more and lead to the best results — those are the most important factors in this decision.
Finally, the one advantage of doing a straight law degree is this: you will have a greater choice of law modules. Generally, a law with politics module will leave you with minimal, if any, choice as to what modules you do. Most, if not all, will be compulsory. However, if you do a straight law degree you will have a significant degree of choice in terms of what modules you choose, particularly in your second and third years. The advantage of this is that you get to explore topics and modules which fall outside of the core qualifying modules. For example, a law with politics degree is unlikely to provide you with the opportunity to study company, commercial or family law. These modules are optional modules and you will not likely have many optional choices doing a combined honours degree. If you are thinking of focusing on a particular area of law which falls outside of the core modules you should consider this factor when making your decision.