Can anyone help RE Dp's employer requesting that he changes his 'flexible working' pattern?

[Flossish]

basically I am a nurse and DP is a pc. When I returned to work last may I was bascially offered two working patterns to fit in with the needs of the ward based around the hours I could do. We opted for the one (of course) that gave us a better work life balance and meant that one of us was always home with the children. I was offered these shifts as they met the needs of the ward, as per the flexible working legislation. Dp's employer agreed that he could work 10 hour days Monday to Thursday. Since he has done this three other people also with flexible working have Fridays off. The 'boss' has now realised there is an issue with giving other employees annual leave on Fridays due to this. They have asked everyone who does have fridays off (apparently several people out of a team of nine!) if they could look into changing the day. For us it would prove very difficult and mean putting our 17 month old daughter into childcare from 7-5, which really isn't something we can afford, is a long day for and will probably be hard to find!

My questions are, is it right that they can try to change a previously agreed arrangement when it seems that the situation has been mismanaged (ie they agreed to people after DP to have the same day off without recognising that adequate service could be provided). Dp is in a flap but going to respond that it isn't possible, but if it came to it could they make him change?

I've tried to google this and found lots of info about gaining flexible working but none about loosing/changing it!

It would depend upon what the original agreement says. Mine was for 12 months initially and was then to be reviewed, and I was allowed to continue on my 4 days with a Monday off. You will need to look at your letters offering the flexible working.

Is there any way of you altering one of your days so that you are off on a friday?

What is a pc by the way (I only know of a computer!).

If you put in a flexible working request that is agreed, the new terms and conditions are permanent. The only exception is if an initial trial period is agreed between the employer and the employee, normally 3 months or something, or unless a temporary change is specifically negotiated, which your DH would obviously know.

But basically, once it's agreed, it's a permanent change to your t&cs, so it's no easier for an employer to change it back than it is to change anyone's terms and conditions, and to do that they need consent. It sounds as though they are asking not demanding at the moment, so he should not feel afraid to say no, he has good reason, and he was the first of them anyway.

If it comes to it, technically an employer can force through a change to terms and conditions by terminating the employees' employment and reemploying them, then risking unfair dismissal claims. I doubt it will get that far, and as your DH had this arrangement first anyway and has had it in place for quite a while, he should regretfully refuse to amend it.