I need to write an essay of 1200 to 1500 words on this topic :

"Our unwritten constitution rests upon a separation of powers" Discuss

It is on the UK unwritten constitution

There is no need to put footnotes or bibliography, and the references when copying from other sources can be put in a bracket at the end of the sentence and I have to use the power of 3s, and develop my essay using only 3 arguments. I have to write introduction, body and conclusion.