We will be in Great Britain in May and June. I need the names, address and webpages for car leasing companies that operate out of London or Bath.
Sorry, but to list these would be a very long list! I suggest that you google this with your exact dates to see the various options. I always use Holiday Autos, a consolidator.
AutoEurope, Kemwel and Gemut are often recommended to Americans heading to Europe. I have not used any of them myself. Dealing with three of four consolidators would be a lot easier than seeking out every local firm in London + Bath, and the conventional wisdom is that it is often easier to rent through one of the consolidators.
Use your question and conduct a Google search. Should be fairly easy.
When you do your search, I suggest you do it under'car hire' rather than 'leasing'. In the UK at least, the latter means a long-term hire, usually of at least several months.
The French car leasing programs (which will deliver a French, left-hand-drive car to London) are Peugeot, Renault (www.renaultusa.com), and Citroen.