Change of Terms and Conditions/ responsibilities, Job Description etc In accepting the pay rise that's been acknowledged by both parties. If we're talking about Thresher or Bottoms Up which is what it sounds like, there's a fair chance that there's some kind of PRP by way of bonus tied into the stores performance too, although Brewers are notoriously poor employers and this is unlikely to be a major consideration.
The only way you might be able to swing this I'd suggest is if there was a probationary period that you successfully completed (typically 3 or 6 months) and then invoked reasons other than 'being unable to cope' for requesting the transfer. Even then I'd be amazed if your employer would be prepared to return you to a smaller store on the same package, unless you could prove (or give them sufficient grounds to believe you could prove) that they'd contributed to the situation. You're potentially wandering into dangerous territory though, and it's tantamount to playing poker for high stakes.
I don't fancy your chances to be honest. The only way I could see you pulling a stunt like that would be if you could prove detriment through the employers culpable negligence etc and thus try and claim an industrial injury brought about by failure to discharge a duty of care in line with the 2004 Employment Act (I think?). It's hard enough to make legitimate negligence stick though, as I seem to think it involves having to prove the existance of conscious mind that links the failure to a wanton action. In addition to that you need a demonstrable log of incidents, and invariably medical testimony to support your allegation.
I wanted to bring a case against my Employer recently regarding a work related suicide, which would have been stronger at prima facie than what you're describing. Suffice to say, the Unions solicitors are paid a retainer, and tend to pick the low lying fruit when it comes to taking a case, and baulked at this one, recognising (correctly) that it wouldn't be easiest one to win. If you could get them to accept an element of contributory negligence then you might be able to negotiate an arrangement/ compromise agreement (though you're strictly speaking you're not leaving their employ), but the same principle kind of applies. Your Regional Manager will have some latitude, but bear in mind you'd need to be able to demonstrate 'cause and effect', and the Regional Manager would need to be sufficiently scarred that you had both the ammunition and means to go through with any claim.
I think you'll struggle to be honest. (I'm not sure even I would try and make that one stick); unless it was part of wider picture, and I was trying to establish a position that allowed me to negotiate something away, which I didn't fancy I could win anyway. The only other variable factor of course is the 'indvidual'. Some people are hard nosed bastards, others can be wobbled (especially if there's a wider aspect in play that you don't necessarily know about).
If I were your boss, I wouldn't agree to your request for transfer on same pay. But then there might be a sub plot? If I were your Boss, and had recently been put under pressure by my Boss, about some of my activities/ poor management, I might be prepared to sweep something under the carpet and deal, if I thought there was a chance that it wouldn't portray myself very well should it come to light. Be aware however, that having boxed someone into a corner thus, they'll remember!!!
If you wanted to soften the blow you could try some stunt along the lines of how much you'd learned from being in the bigger store etc and that you felt you'd be able to translate this experience into improved trading performance and try a PRP route? At the very least though, you'd be expected to convince the Regional Manager you could deliver on any 'action plan', so would need to present something. Even then, it's my best guess they'd say alright, go and prove it, and we'll talk again in 6 months depending on how well you've done.
Salary protection is normally covered by TUPE, and I don't believe it applies in this case given the employer is the same. It's possible there might a corporate policy, but this usually occurs when the employer is making changes to contracts, re-structuring etc That it's you whose instigated the change, would restrict its application and your scope for manouvere
