Spouse Visa but not allowed to work

Hi I'm on a spouse visa due to be renewed in December 2015. It means I now have approximately 1 and half years valid stay in UK although I'm planning to renew the visa June next year. I have been working since I came to UK but I decided to change jobs since I was changing towns. However I applied for another job and got it, went through all the training procedure only to receive the contract saying I am now their employee but I will work for them when I have renewed my visa in December 2015. this means I have to work for them in January 2016????? I find this absurd and discriminatory. Is this how it works? is there a set time I should work in UK as a spouse?

You have the legal right to work without restriction on your spouse visa. I suggest you ask your future employer their reasoning behind the contract they have issued. Ask them to call the HO helpline for employers if they are concerned about your right to work. Here's the link you can give them:
employercheckingservice@homeoffice.gsi.gov.uk

I'm confused when you say your visa is due for renewal in December 2015 but you intend to renew it in June?

My partner had the same on UPV, went through all the interviews etc then they said they would employ her only when she got ILR, then due in a few months.

To be fair you can understand their reticence, there is a chance ILR won't be granted etc, leaving them having to re-recruit...

Anyway she told them to stuff it anyway lol!

Your contract could also mean that it is until December 2015 and then ongoing dependent on your visa extension. Best to check with the employer.

I had this exact issue with my spouse visa where my employment contract, though 'permanent', was only valid for as long as my visa was valid. An addendum was added to my employment status after I got ILR.

Like Casa, I too am perplexed as to why you want to renew your visa 6 months early?