Twitter pokes fun at Cameron's 'now this is really serious' face

Oh dear, David Cameron.

The British PM posted a picture last night, supposedly of himself talking to Barack Obama about the turmoil in Ukraine.

David Cameron looks so stage-serious in the pic, that it didn't take long for a gallery of celebs to start taking the mick.

Here's the pic:

I've been speaking to @BarackObama about the situation in Ukraine. We are united in condemnation of Russia's actions. pic.twitter.com/7Rk2k8iOIK

— David Cameron (@David_Cameron) March 5, 2014

Patrick Stewart called on his wealth of theatrical experience to chime in with his most serious face, with a tube of wet wipes for a prop:

.@robdelaney @David_Cameron @BarackObama I'm now patched in as well. Sorry for the delay. pic.twitter.com/elLQcKcV3w

— Patrick Stewart (@SirPatStew) March 5, 2014

US comedian Rob Delaney out-mocks the mockers with his 'we're on the brink' face, and a very serious tube of toothpaste.

.@David_Cameron @BarackObama Hi guys, I'm on the line now too. Get me up to speed. pic.twitter.com/xhmJG5KpxT

— rob delaney (@robdelaney) March 5, 2014

Writer Michael Moreno patched in via his dog phone...

@SirPatStew @robdelaney @David_Cameron @BarackObama Ok, guys, thanks for holding. pic.twitter.com/ih36KWU3Tb

— Harvey Moreno (@MacMoreno) March 5, 2014

And here's a gallery.:

Many, many others had a poke:

PM logic: 'I'm on the phone to a world leader about a country in crisis - time for a selfie' http://t.co/Aj88WR3Y2v pic.twitter.com/OwzXt3NQJD

— Charlotte Meredith (@chmeredith) March 6, 2014