Back in the summer, Matt (who runs the on board passenger information systems for Thameslink, and is a voice that you will recognise) asked me if I'd like to be the voice announcing the Brighton Mainline Closures that are coming up I said yes!
But actually, I forgot all about it, and it wasn't until I started getting people tweeting me about it that I thought I'd better go and and try and catch myself saying it ...
The "Must play" DfT announcements that are referred to are the 'See it, say it, sorted' ones which play at :25 and :55 minutes past the hour. The female voice that does the other announcements is Julie Berry.
Oh, and if you do travel on the Brighton Mainline you should be aware of the closures! Here: https://brightonmainline.co.uk/