55 / 60 MPH in the middle lane.

I drive my m/home, generally, at a fairly steady 55 / 60 mph, as many other m/homers & caravaners do.

I don’t really want to move across two lanes to over take a vehicle steadily motoring along at 55/60 mph in the middle lane that has been in my view for some while.

So I tend to catch them up and gently cruise along with them using the inside lane and  hopefully with my vehicle being seen from their nearside wing mirror.  Although I have my doubts the driver would use the mirror.

Just wondering at what point this might become illegal, / dangerous to pull along side but not undertake, or maybe a tad in front so that I am in their view.

Rgds