That part of the Highway Code is not law, it is advice, the exception being about the hard shoulder, and even then, that is now wrong to a degree as some Motorways now use the shoulder as a live lane Yes, Sec 38(7) of the RTA 1988 states "A failure on the part of a person to observe a provision of the Highway Code shall not of itself render that person liable to criminal proceedings of any kind but any such failure may in any proceedings (whether civil or criminal, and including proceedings for an offence under the Traffic Acts, the M1Public Passenger Vehicles Act 1981 or sections 18 to 23 of the M2Transport Act 1985) be relied upon by any party to the proceedings as tending to establish or negative any liability which is in question in those proceedings." The Highway Code is a way to establish fault. So overtake on the left and if there is an accident you are more likely to held liable.