Does anyone know if there is anything in employment law about this? The argument against is that it's a new job, therefore time employed by the company in a previous position should not be relevant. But I can't find anything for or against this.

Quick question: about 7 employees are on the same pay scale, all on various points of that scale depending on how long they'd been employed by the (public sector) organization in question in the UK. All had the same job title and job description. All 7 employees were promoted, and given new job titles and job descriptions and moved up a pay scale - once again, all had the same new job title and job description. However, the employees that were on lower points on the previous scale, where once again given lower points on the new scale. From a legal standpoint, is this perfectly acceptable, regardless of the fact that they have been given new job titles and descriptions? Thanks