OP - welcome to the Forum, you might like to post an introduction thread so people know who they are helping
No, you can't - loads of reasons why not, mainly to do with currency (if your house stays at the value but the FX moves, suddenly their asset is worth less), housing market (Swiss banks don't know the property values) and asset security (if you default, they need to navigate UK law, rather than familiar Swiss law).
Also - if it were possible, everybody would do it.....and arbitrage would say that Swiss mortgage rates would increase!