Thanks Vixta for being the only one of 52 people who viewed this post to bother to even post a reply.

I sometimes think I should stop replying to other people's threads. Oh well.
Thanks for your advice. I know they are sort of breaking the law, it's just if I stay on SSP, any SMP I get will be severely reduced. I sat and worked it out last night:
Option 1) Stay off on SSP and then straight into SMP - working it out taking in to account my other job, child benefit and CTC, I'd get £115 a week til end of March when I finish up in other job, then 90 a week for the few weeks til she is born, then 131 a week until I return to work.
Option 2) Go back to work in mid December and then leave on maternity as planned on 1st Feb. Get 164 for the first 6 weeks, 148 for a few weeks, 123.06 for a few weeks and then 164 for the remainder of my leave.
Option 3) Leave job as don't intend to return anyway, and claim MA from 1st Feb. I'd get no money in January as would have left my main job (will get a bit from 2nd job), then will get 123.06 a week until she is born, then 164 a week from when she is born until I go to work.
So basically, money wise, options 2 and 3 look best. I guess what you say about staying employed and not being pushed out is also a factor though - they want me out. They love people so long as they can take take take from them, but when they need something back, they push you out.