I wonder what his objection to PMB's is?
Quite a bit of significant legislation started its life as a PMB, including the Act that legalised abortion back in the 60s. I also have a (dim, very dim) recollection that the campaign against FGM first got a mention in parliament via a PMB.
Perhaps that's the reason, he doesn't like PMBs because they're often used to advance women's rights, the misogynist fossil.