Not sure which gcse grades you need for this, but I don’t see why you shouldn’t have a go.
I knew someone on tsr who got in for history with 2 a stars. However there are fewer places for history and politics.
Maybe you could volunteer in a museum or stately home?
Or maybe get involved with politics at local level. I know someone who is a politics student who spoke on a motion at the Lib Dem conference and his speech actually appeared on the bbc!
My son was offered a work placement by his local mp, so it’s worth emailing to them.
Or you can also ask them if you can have a tour round the Houses of Parliament. My sons and I did this, and we got to hear a major speech in the House of Commons