When to give notice so as not to have to pay back maternity pay?

[Ro62]

I'm pregnant with second child and in a job where I have to give 6 months' notice. I'm entitled to a year's mat leave with good employer benefits on top of SMP, but if I don't return to work for at least 3 months at the end of the mat leave, I have to pay it all back. DH has just lost his job, so we can't afford to do that.
My employer doesn't know, but I've just been offered the same job nearer to home, with the same pay etc. I'd like to take this job when I go back from mat leave, and they're happy to wait for me (will sign a contract so I know it is safe).
I don't know when I have to give my notice, though. As far as I can see, I'd need to give my current employer notice 6 months before I want to leave, then go back to work for 3 months before the date I leave. (So give notice on 1 December, then go back to work on 1 March and leave/start new job on 1 June). Does anyone know if this is right?
Also, what if I give 6 months notice (as required in my contract) and they say they want me to go in 3 months, do I have to return to work immediately so as not to have to pay back the benefits, or can they not shorten my period of notice?
sorry it's so complicated! Very grateful if anyone's done this or has useful websites to find out where I stand.

[MovingAndScared]

I would have thought that if they are asking to you leave early they couldn't ask for the maternity pay back -but there are better qualified people on this site so don't take my word for it. I was made redundant 4 months after returning from ML and I should have been there 6 months as I was working PT - but I got it in writing they wouldn't ask for the money back

[Grevling]

At worst you'll have to give 6 months notice and work for 3 of those months.

Of course you could ask to leave by mutual consent in which case you can ask to leave early without having to repay mat benefits. They will either agree to this or not. They can't force you to go back before your year of mat leave is up but they also don't have to let you leave before the end of 6 month notice period.

If they say they want you gone in 3 months then its all about negotiation. They can't force you to leave the company but could stick you on gardening leave for 6 months in which case you wouldn't be able to work for others.

[frostymomma]

In addition, if it's worst case scenario and you do have to return to work for 3 months, you could use holiday entitlement (any banked holiday from the period of your mat leave plus that owed to you for the 3 months you return), so that you are actually in the office for the minimum amount of time. If you have a lot of holiday owing to you, it could be used as a good bargaining tool to get them to release you early without forfeiting your mat pay - it may not be worth their while to get you back up to speed, have you building relationships, etc. if you're only going to be there for a few weeks.

Best of luck and congrats on the new job!

[Ro62]

thanks a lot everyone, that's really helpful. It's funny, I've not really felt like I could celebrate/feel happy about new job as I've just been worrying about the logistics - this feels like a weight off my mind. I appreciate it a lot.