Hi, are there any websites, which present a list of excellent vocabulary I can incorporate into my essay, so every sentence sounds like its critiquing the debates?

or any guides to create complex sentences (interesting sentences), which integrate numerous points within a short space - so the reader is compelled to read to the end...

does anyone know any good websites which can advance this way of writing to a high standard?

No being the short answer. Writing to a high standard comes with practice. Try by beginning with a LOT of additional reading (don't start with Nature which will result in confusion to a high standard 8-)) to get a general idea of how syntax should and can flow and then get writing. Pass on your work to a friendly and willing invigilator and listen to their feedback. Then practice some more... continue ad infinitum.

This might be useful - someone posted it a while back, it's a resource for academic writers. http://www.phrasebank.manchester.ac.uk/

Ultimately though, you can have a thesaurus for excellent vocabulary, but each sentence will only seem like it's 'critiquing the debates' if you've actually got something to say and know what you're talking about, which comes with practice, as Hypothesis said.

I don't think critique is a matter of using big words, but of really understanding the subject and being clear on what you want to say.

I completely agree with Juno. Just make sure your work plainly and clearly states your thoughts. The temptation to high-brow vocabulary tends to irritate most readers, and looks like you've tried too hard.

Here are some 'signposting' words, that can help to make your sentences flow:
http://cedar.humanities.curtin.edu.au/TeachingMat/OLLD/Argument/12-0.cfm

In terms of picking up vocabulary, the best thing you could probably do is read, read, read! Pick up a bunch of papers from your field and make a note as you go along of any words that you wouldn't normally use yourself, or aren't confident you know the meaning of. Try incorporating them gradually into your work.

Get people who you trust and who have good writing skills to look at your work from time to time and offer honest feedback on how you're doing.

Go to a decent bookshop and have a browse of books in the grammar/style section. Only you will know what suits you and is written at the right level for the skills you want to develop.

Be aware of the audience - you must pitch your writing differently according to who is likely to read it, and what kind of writing (essay, journal article, lit review, informal article) you're supposed to be doing. I hope it doesn't sound patronising to point this out. It's just that I've recently been doing some editing or a magazine written by undergrads, and the number of them who don't know how to write *appropriately* for the type of piece that they are doing is quite depressing.

Finally

Beware! If I start reading a 'complex sentence' that 'integrates numerous points within a short space' I can't promise you that I would be 'compelled to read to the end'! Sometimes it can work, but other times it can make people fall asleep. I would rather read something where the emphasis had been on good sentence/paragraph/essay structure than where a lot of effort had gone into hypercomplex sentences.

If nothing else, trust me on the reading!