Hi Jude,

I used to live in London and attended a conference and an evening dinner at the Royal Horticultural Halls in Westminster. It’s the perfect place for this kind of thing and really nice too!
Apart from the obvious places to stay like the Ritz and the Savoy (which are a little pricey!) I’m not sure about hotels but you could search Google for ones in Westminster and I’m sure it will bring up tons.

Here's the link

Horticultural Halls

Hope this helps…

Sarah-Jayne smile

"A hero is an ordinary individual who finds the strength to persevere and endure in spite of overwhelming obstacles."
Christopher Reeve - Still Me