Where a solicitor or an incorporated practice authorised by and acting for a client employs another solicitor or incorporated practice or a licensed legal services provider he or, as the case may be, it shall (whether or not he or, as the case may be, it discloses the client) be liable to the employed party for that party’s fees and outlays, unless at the time of the employment he or, as the case may be, it expressly disclaims any such liability.