No!
Its there for a reason. Ignore any scene queen who comes along to tell you to run without one. If you get pulled without a numberplate in the correct place you'll be fined £100 and it will be deserved. Exceptions are made for certain cars, ie some cars with no area that possible to put them on, ie some supercars blah blah blah.
It HAS BE......
"vertically or, where that is not reasonably practicable, in a position as close to the vertical as is reasonably practicable"
All the the legal stuff you'll need.....
http://www.legislation.gov.uk/uksi/2001/561/regulation/6/made 
