I'm in quite a difficult position. I work in a professional services company and am considering switching from client work to internal business development. This has easier hours and much more flexibility, but entails a ~25% pay cut and reduced long-term pay/progression compared to the partner track. I've already spent some time in the past temporarily in a similar role and think it fits our family's needs best - I have a 2 year old, a husband who works long hours and is away a lot, and we live nearly 2 hours from our London offices (where both our companies are based).
I've found an ideal internal role and applied for it, but I have a challenge around when I tell them I'm pregnant. Normally I would take the approach of waiting until I was offered the role considering I'm still fairly early in the pregnancy (process likely to take ~6 weeks and I'm a very strong candidate). I would then likely start the new role in July.
However, our company enhanced maternity pay is calculated from your salary on the date you go on leave, not the statutory pay date at 25 weeks (which would be my current 25% higher salary plus much bigger bonus). So I would likely be looking at only doing this new job for 8-10 weeks then going on leave and potentially losing tens of thousands of pounds of maternity pay due to the new lower salary. So I'm wondering if it's helpful to tell them in advance during the interview process, as we might be able to come to an agreement that I officially start in the new role after my maternity leave ends and I stay in my old role until then, as they'll need to find cover for me anyway. I think this might be harder to negotiate if I only tell them after the offer is made, as they will feel I misled them and be less likely to be supportive of this concession. I think there's a fairly low chance they'll agree to this suggestion either way, so I don't want to do anything to reduce that probability.
What would you do?