It has to be Diane Abbott. She is the the undisputed clown of politics when it comes to car crash interviews and letting her party down. It would also be reasonable to say she only gets elected because of the large ethnic vote in Hackney, and it being a very safe labour seat.
Look at her track record. She openly criticises others for racism, rightly so, and yet has voiced racist views herself on numerous occasions. Too many to recall. Her hypocrisy around private schools, her inability to count, her trying to bluff her way through interviews badly, her patronising personality, the list goes on ad nauseum.
There is one thing I admire her for though. That is her courage in continuing in her post despite often despicable comments and racist abuse that she has received.
Awful constituency MP, never gave a flying **** for anyone but herself, and anyone who criticises her is basically just Hitler (including the Lib Dems that she later got cosy with when nobody else wanted her)