My two penneth worth.......
I'm pretty pro active as a father and perhaps a little confrontational
I would contact the police and explain that you have joint parental responsibility and that your ex is harming your child by denying proper contact. You are intending to see your child at the nursary but are worried that your ex might turn up and cause a breach of the peace. Get a log number from them
Go to the nursary, take the birth certificate and your passport, explain the situation to them and make it clear to them that you have a right to see your child, a right also to learn of the progress your child is making and will do so at a convienient time of the day (for them).
They'll probably tell your ex of your intentions and she'll worry that you may "snatch" your child away. Bet she rings you up
