Working extra hours for less money

[rockingaroundthemulberrybush]

I am currently contracted to work 15 hours per week on a pro-rata salary. A colleague of mine is off sick just now and it looks like he might be off for a while, so I was asked to work an extra 10 hours per week, doing exactly the same job as my current job to pick up some of his work & keep things ticking over. I have taken this on temporarily until colleague returns to work.

I received my payslip this week and I have been paid at a significantly lower hourly rate for these extra hours - about £6.50 gross/£3.80 net. To put this in context, I was TUPE'd into my company about 5 years ago and am aware I am on a higher hourly salary than my colleagues for the same job due to what I was paid at my previous company - due to TUPE rules, my salary was protected. If I am covering my colleague's work and it is exactly the same job, do I have the right to insist I am paid at my usual salary or do I have to suck it up (or refuse to do the extra work going forward)? To complicate matters, I suspect that if I was to be paid at my higher rate, I'd be receiving a manager's salary (or higher), as my current employer does not pay well.

I've a feeling the answer is that I'll have to suck it up or refuse the extra work, as this is my colleague's salary, but I just thought I'd ask mumsnet!

TIA

They can't pay you less than minimum wage - am assuming you're over 25 it's £8.72 but I would expect to be getting the same hourly rate as you do for going your own job.

*doing

ACAS have a free helpline and can advise, or, if you're a union member speak to your rep. It doesn't sound right to me either so it's worth checking.

Surely your rate is your rate and when they asked you, the knew your rate? And that is under nmw so not allowed anyway?

Apologies I appear to have confused things. The figures quoted above are how much less per hour I'm being paid, not my hourly rate.
So my usual hourly rate - £19.00 per hour gross (I am salaried but this is what it works out as)
New hourly rate for extra hours - £12.50 per hour gross

= £125.00 per week gross for 10 extra hours instead of £190.00 gross.

Well rhats better, but my point stands. Your rare is your rate and they knew.your rate when they asked.

Thanks for your reply.
Does anyone know if I've a leg to stand on here or if I have to have a difficult chat with my bosses?

I would certainly query it, is there an HR department to go to.

I suspect what they are doing is legal though. I am a nurse on a relatively senior rate, but if I pick up extra hours via our burse bank they are at a much lower rate of pay (so I dont).

Thank you. That's a good and understandable analogy Stompy.