iCloud emails no longer push to iOS devices

As of last Saturday (this did not correspond to the installation of iOS 9 patches), my iCloud email no longer pushes to iOS devices. When using OS X Mail, emails arrive instantly but both my iPad Air 2 and iPhone 6 are no longer receiving push notifications. After the issue began I updated from 9.0 to 9.02 and it didn't improve. I also tested on a retired iPhone 5 with the same results. I tried my wife's account on my phone and it receives instant push notifications so I do not believe it's device related. Setting the account to fetch does not work either. I had to add a second account to the phone manually using IMAP settings to get fetch to work (this also doesn't receive push) - and with fetch set at 15 minute intervals, emails generally arrive every 30-40 minutes. Has anyone else experienced this?

Thanks