He has received much critical acclaim for this, and is now a genuine minor celebrity.
Sadly, this appears to have gone straight to his head, and now, like many other people who have a couple of perspex trophies on their mum's mantelpiece, he thinks he's fucking Bono.
He believes that his views of the world beyond the TV cameras are something we should hear.
So, this star of a fucking kid's TV programme has decided to give us all the benefit of those views. And the mindless, showbiz-obsessed media have of course lapped it up and regurgitated it.
It turns out that Doctor Who thinks we should all vote Labour in the upcoming election. He will be. He always has. And he thinks you should too.
But like every single other Labour supporter, the good Doctor has no fucking idea why we should be voting Labour. Oh no.
In common with every other mindless NuLab sycophant, he has no clue what's good about Labour, but plenty of views on what's wrong with the opposition.
Apparently, David Cameron, the Leader of the Conservative party is
"..a terrifying prospect."
"He's a regional newsreader who will jump on whatever bandwagon flies past."
Oh really? Well, that's a convincing argument, isn't it, David? Is that why we should choose Brown again?
Let's forget about what your fuckwitted, slack-jawed, one-eyed fellow countryman has done to this once great nation, shall we, and focus on the really important stuff, eh?
And, David, what particular Labour policies are you keen on? What's good about NuLab?
"..they need to sort some stuff out. But they're still a better bet than the Tories."
Oh. Right. Incisive stuff. Bring on the election: we know what to do now. The Doctor told us.
Naturally, desperate Labour activists have leapt on this fucking nonsense. Prescott has jumped on it quicker than he'd pounce on his Diary Secretary, even if she were clutching a couple of pies.
Twitter has been alive with references to the story, and Labour probably fondly imagine that this imbeciles ramblings have won them thousands of extra 'yoof' votes.
We get some idea of why this witless mummer is shilling for the woefully inadequate Labour party when we learn that he was brought up in Paisley, Glasgow: part of Red Clydeside, where every seat has had a Labour MP for nearly 100 years. One of those areas where a fucking pig with a red rosette would win by a landslide.
And then, of course, Tennant made his personal fortune in the bosom of the BBC. The Clydeside Socialist mingling with all the Champagne Socialists. What a heady mix.
All completely isolated from the real world, but all very willing to tell that same real world what to think.
But you know what, David, darling? We're not interested in your views of what's wrong with the eeevil Tories. And we're not interested in who you choose to vote for.
We might be prepared to suspend belief on a Saturday night, and pretend that you really are floating in outer space, but we still don't fucking believe that you know what's best for us out here in the real world.
Stick to what you know, luvvie.
++UPDATE++: the great Cranmer thinks along the same lines, but is - as always - much more eloquent. Damn him..