vinyl over bathroom tiles

[Kat74]

Is it ok to put vinyl flooring over the tiles on my bathroom floor? I've been advised that the floor should be screed over, but the tiles are only a couple of years old and in good condition so I don't want to damage them.
The vinly shop said that if I don't do this the grooves inbetween the tiles will show through the vinyl so it will need an underlay. is this correct, or is it ok to put the vinyl straight down?

 

[breezer]

i agree with the shop

 

[TexMex]

You could always take the old tiles up first and put them into storage somewhere for safe keeping.

 

[smiths]

The tiles will show through.