Excellent thread from Sean Jones who is an employment law silk and lays out the decades-old background to the decision about equivalent value, single source etc. It's useless for me to simplify this - it's worth reading.
I don't understand how equal pay works in practice. I'm in a role that does not have salary bands and everyone with the same job title and responsibilities earns different amounts based on what they negotiated at interview. Most were recruited in to the same role within 6 months of each other. Some were told there was no negotiation and accepted the salary offered. There is disparity of 3-4K between the lowest paid (female) and highest paid (male).
There is disparity in industry experience but not always in favour of the men who are paid higher.
But as I understand it, we can all be paid slightly different based on our CV experience etc. No pay reviews have taken place as we all have less than 12 months service, so salary cannot be based on performance but only on offer after interview.