LSE BSc Econ or Politics and Econ

LSE BSc Econ or Politics and Econ
I’m oversea student, undoubtedly pure econ is super competitive ( but more offers will be given) while for PE it is less competitive ( few people in my country apply this course, but admit less than 100 people per year)
No matter which course I apply for LSE, I need to take TMUA cuz I apply for cam.
Currently, I don’t have any activities related to politics (but can do some)
Should I start to do some relevant activities to apply PE or try to work on TMUA to reach a high score and apply for Econ?
Pls give me some suggestions!!