Welcome to Twitter Mrs Brown, or should I say @SarahBrown10

It’s one thing to have rock star comedians like Russell Brand on Twitter. Or talk shows hosts like Jonathan Ross. Or perhaps an erudite thinker, writer and presenter like Stephen Fry.

It’s quite another to have the Prime Minister’s wife on Twitter.

Whatever you think of her husband’s government – or, indeed, her husband – Sarah Brown is pretty well regarded by the bulk of UK society, and especially women. So it’s possibly worthy of note that Twitter has not only hit a rich seam of celebrities in the the UK, but is percolating nicely through to people who are highly likely to take the site even more mainstream.

How do I know it’s the real Sarah Brown? In the usual manner, I’ve had it confirmed by a source at Number 10. It’s definitely her either typing the actual tweets or authorising someone to do them on her behalf. “It’s not a spoof” said my well-placed source. Certainly, references to “Michelle and Carla” and phrases like “Back in UK ready to focus on G20 this week. I want to make sure the spouses get the most out of their stay in London” read like she typed them herself.

Right now she has 42 followers (I was number 42). Let’s see how many she has in a week. It will be an interesting test of Twitter’s mainstream adoption in the UK, if nothing else.