British Prime Minster David Cameron became a father for the fourth time today when his wife Samantha Cameron, 39, gave birth to a girl.

The little sprog couldn’t wait to see the light of day, arriving three weeks early to interrupt the Camerons’ family holiday by the Cornish seaside.

“It all happened very, very quickly and the baby popped out at about 12 o’clock,” the prime minister said, showing his acute perception of the birthing process.

Mr Cameron’s daughter was born by Caesarean section at the Royal Cornwall hospital, in Truro, weighing 2.7kg. Three hours later, he stood out the front of the hospital declaring: “she is an unbelievably beautiful girl. I am a very proud dad. Baby and mum seem to be doing well.”

The baby is yet to be named, but Mr Cameron, 43, reckons “Something Cornish in the middle” would be apt.

She is the couple’s second daughter following their heartbreak last year when their son Ivan died aged six after battling cerebral palsy and severe epilepsy.

Mr Cameron said their other children – Nancy, six, and Arthur, four – were “thrilled and bouncing up and down” with excitement.

The latest addition to the brood is only the third baby to be born to a serving prime minister since 1849.  The last one was Tony and Cherie Blair with their son Leo in May 2000.