Throughout the Duchess of Cambridge's second pregnancy there has been no confirmation of a due date or the baby's sex, let alone its name.

But that hasn't stopped Brits taking a punt on all things royal baby. They're betting on everything from birth dates to birth weights. Tens of thousands of wagers have been placed across the nation.

Bookmakers William Hill says an extraordinary 83% of bets have been for a girl.

"I don't genuinely believe that they know themselves, but I think everyone expects them to be the perfect family," said Rupert Adams, William Hill spokesman.

"And the perfect family on paper is obviously a husband and wife, an elder son and then a daughter. An heir, then a spare, as they call it. And I think that is the sole reason. So if you fancy a little punt yourself this time then the male bet is absolutely fantastic, you can get 11-8 out there, almost double your money and as far as I am concerned it is a 50-50," he said.

Two big gambles on one girl's name, in particular, has shortened the odds dramatically.

"We've had two bets of £500 both on the name being Alice and this is massive, massive bets for us. The average bet on this type of market is about £3 to £5, so a bet of this size is unheard of. And what you will probably find is that somebody's heard something that they've said 'If it's a girl they might call it Alice,' so I don't believe that they actually genuinely know, but they certainly think they do," said Adams.

The odds on the new baby being called Alice are now 6/5. Coming in second is Charlotte at 5/1 and third favourite is Elizabeth at 6/1. Another popular choice is Diana, after Prince William's late mother, at 20/1.

As far as boys names go, James is attracting a lot of bets with odds of 8/1. Other popular names include the traditional Arthur, Alexander and Albert.

For the true gamblers, the longest odds are on the baby being called Tyrone, Royston or Crystal, all at 1000/1. Chardonnay, Waynetta and Winston would also give punters a decent return with odds of 500/1.

Word on the street outside the hospital where Kate will give birth was that she will deliver a little girl. A small group of royal enthusiasts have already been camped outside on hospital benches for the past week.

"I think it will be a little girl and I like Charlotte Elizabeth Diana, I think that's a lovely name," said Maria Scott.

"I don't know about Alice. I think a name like Elizabeth or Victoria. They go for very traditional names in the royal family and we don't know that it is a girl. I know there is a lot of thought that it is, but you know, I was wrong last time, I said it was a girl and it was a boy, so you know..." said another royal fan, Margaret Tyler.

Last time it took the Duke and Duchess three days to announce the name of Prince George Alexander Louis. The reported due date for Kate is around 25 April.