How does Paternity Leave work in the UK? My partner tried to speak to his boss today about it (although I think she was having a particularly bad day...)

I assumed the father was able to work until he got the call baby was underway, or able to call work as soon as contractions started at home?

His boss has said she needs an exact date his leave will start. Im due March 11th but all the babies in my family have been roughly 2 weeks late. If he leaves from 11th, he may not be around for after the baby's born?! I don't get it!

She's also said if I was to go into labour whilst he was in work, it would be his responsibility to call another manager to come in to cover for him, and he'd have to wait for him to show up before he could leave, surely this isn't right?!

He's one manager of about 5 of a department in a big place - the same place I work. I know plenty of other workers in our company that have just said they're going, wife's in labour and will be returning after 2 weeks, why is he any different?