Working with agency for the same company sfter redundancy

I have volunteered to take redundancy from my present job to save Someone else’s job as I have my hgv 1 licence and the other guy has not. We both work in the office . This helps both parties 1.he moves into my job.2.it save me 350 pound per month on fuel costs. There is an oppertunity to work as an agency driver or self employed for the same company 10mins from my house . I haven’t said that I will take it but the person that has given me this option has been approached by the GMB area rep and was asked why he was giving me a job ,this person explained that he was not giving me a job and that he was giving me an option (if I wanted to take it) to work out of the same company but in a different location either as an agency driver or self employed . The GMB rep stated that the union were not happy that the company was giving a class 1 driver redundancy when the company are currently taking class1 drivers on.The person explained that I was no longer employed as a class 1 driver and that I was actually employed as a fleet controller. The GMB rep stated that the union was not happy with this situation and that they where taking it to HR. The guy that has given me this option was in a conference call on friday with HR who said that this is not allowed and that if you worked for A company and left under redundancy that you cannot work with that same company no matter how many different individual branches that company has. I cannot find anything anywhere that states I cannot work as an agency/self employed worker ? Can anyone clarify if this is true or is it ■■■■■■■■. As far as I see it I am not working for them I would be working for an agency so they would not be paying me directly and I cannot see where the problem lies. Please if you can help with this please go ahead.

I always thought that it was the position that was redundant not the person so if they made you redundant they could not employ or transfer anybody to your job for a period of time why don’t they just transfer you be a lot easier

We had 90 drivers made redundant ,then were x amount of drivers short the next week ,so agency were brought in,that included drivers who were made redundant the previous week ,
N.b there was no union involved though .