UK data add-on: will it work roaming, like my usual plan?

I am in the uk atm, and the data on my usual plan is about to run out. So I plan to buy a UK Data Add-on. But will this add-on data still work in France (where I go next week) in the same way my usual Plan would?

Will you be in France for a short time AlistairD4? I believe that any data add-on will work as usual as France is part of the Roam like Home destinations and you don't go over the 30GB allowance for roaming.

Hi Martin,
Thanks for coming back to me. I was trying to ask a Lebara operative on the phone just now- but he seemed equally unsure!
Yes- I am going to France on sunday for a week. But my UK plan has run out of data already, so I have been using UK Data Add-Ons to top up. And I just want to know whether those data add-ons will work in France in the same way as my original plan would have done.
If they do, then that would seem to negate the need for me to also buy a separate Roaming Data Plan add-on as well.
For example, I could buy a 20gb UK Data Add-on for £10. Which is considerably cheaper than a 25gb Roaming Add-on for £20.
Can you confirm please?
Much appreciated,
Alistair