Maxstream is correct, it is going to be very important that you check the agreement that you have with your landlord, ideally you'll have something in writing. You may need to present a copy to your supplier especially if your landlord attempts to give a different picture of events.
So long as the arrangement can be proven, I find it extremely unlikely that the supplier when given the full facts would install a PPM meter (they may isntall one if they not aware of the isutation and are under the impression the landlord is living at the property for example).
If possible It would more-than-likely prove more beenficial for you to have your rent lowered and you pay for your own energy consumption this would give you far greater control of what happens.
Any problems let us know.