We are having a restructure at work and they are dividing current workers into teams. In my team there are senior posts and other posts. Being part time I have been told if I apply I won’t be considered for a senior position due to working part time and they do not have the money to increase my hours to full time. I feel I am being treated unfairly not being considered for the promotion or higher position. They stated that I had asked for part time and they did me a favour, even though they only reduced my hours per day so I still had to have childcare across five days. I have been asking to increase my hours for some time, but they say they can’t afford to. Now I am being prevented from applying for promotion.
I have assumed that all 7 of you in the team do broadly the same job and that the 3 senior and 3.5 regular positions will be doing broadly the same job, with just different levels of seniority.
Once you have made a request to reduce your hours, that is a permanent change to your contract unless both parties agree to another change. Your employer can therefore legitimately refuse your request to increase your hours.
It is unlawful to treat part timers less favourably than full timers unless this is objectively justified. Refusing to consider you for promotion is likely to be less favourable treatment unless this can be justified.
As childcare was the reason you went part time, you might also have a claim for indirect sex discrimination (on the basis that more women than men work part time for childcare reasons) but again that can be objectively justified.
Your employer might try to justify the senior roles being full time on the basis that they need 3 people there full time to support the regular full timers. Whether or not they can do so successfully will depend on the particular circumstances.
They then need to separately justify the decision not to allow you as a part timer to apply for that full time post. They might do so by stating that they do not want to make anyone redundant (if you got the full time post, one of the full timers would have to choose between part time hours or redundancy).
If you feel strongly about the situation, you might want to raise a grievance complaining about discrimination on the basis you are part time as well as indirect sex discrimination. You should bear in mind the short 3 month time limit to bring a claim before the Tribunal and make a decision about whether or not to pursue the matter well within that time.