Martin from your message it appears like you have a home charger unit with a type 2 socket on it but no plug. You can of course use the double ended cable and either leave it there plugged all the time or unplug it and take it with you in the car.
But I want to add that the double ended cable was not meant for home chargers that have sockets and no plugs. The cable was for public chargers that have sockets. Here you can see a public charger with a type 2 socket but no plug. It means you need the double ended cable. More pictures here:
Berkeley Square: charge point in London
Chargemaster also has indoors public chargers that have a type 2 socket but no plug. You can see them on the following page. Notice the card swipe section in the middle.
Wall Mounted Units
The charger you need is this one from this page:
Home Units
HPWC is not needed for home charging. HPWC makes more sense in the US where the electric output is 110V and you need to install something. It is either a 240V Nema 14-50 socket or an HPWC. But in the UK you can have free chargemaster home chargers, thanks to a government grant and even the 240V 16A base model provides 10 miles of charge per hour. For £99 you can get 240V 32A and that provides 21 miles per hour. There is no need for HPWC. The reason why US owners have a HPWC is not because it charges so fast but because their car doesn't have a type 2 socket. The HPWC is the only home charger they can have. They can't use other chargers without an adapter.
On another website somebody mentioned that chargemaster swapped their home unit with another model for free. They also work with British Gas. Those British Gas chargers branded Polar, are by Chargemaster too. So give them a call if you have a charger different than the home charger in this image.
To summarize, the best thing to do would be contact British Gas or Chargemaster and have their type 2 home charger installed in your garage, driveway or front garden for free. If you are driving more than 100 miles per day you could have the 240V 32A version for £99. Home owners without an electric vehicle also qualify for the government grant. If you have relatives you might visit regularly they could have their free type 2 charger installed too. Just contact one of these two places:
Electric Vehicle Charging Offers - Save Energy - British Gas
Welcome to ChargeMaster!
The government grant for free chargers ends in March 2015. Tesla HPWC is expected in 2015 too. Therefore even future Tesla owners from the UK should have their type 2 chargers installed now.