Blair baby: 'It's Jack or Chloe'

Baby boomers: The Blair family

Prime Minister Tony Blair and wife Cherie will opt for chart-topping names Jack or Chloe for their new baby, according to bookmakers.

Both names have headed the Top 50 favourite name for UK babies for the past three years.

And now bookmakers Bet Direct have made Jack and Chloe favourites at 12-1 for the Blairs' fourth child.

What's in a name?

Jack was originally a familiar form of John, but is now firmly established as a first name in its own right.

Chloe means "blooming" and is derived from the Greek khloros for a young green shoot

Other hot choices for the Blair baby, due at the end of May, are Thomas and Matthew and Emily, also at 12-1, and James, Joshua, Charles, Hazel and Charlotte, all at 14-1.

Leo is priced at 16-1 because it is the name of Mr Blair's father and film star Leonardo Di Caprio.

Liam, after Oasis singer Liam Gallagher, is a long shot at 80-1.

Chelsea, after US president Bill Clinton's daughter is also offered at 80-1, but may not be first choice for Newcastle fan Mr Blair.

Out of the name frame: Liam Gallagher

Maggie has the longest odds, with a price of 200-1.

But William Hill has had the most unlikely wager - £5 at 500-1 that Ken Livingstone will be the child's godfather.

Spokesman Graham Sharpe said: "We aren't too worried about the bet on Ken Livingstone being the godfather - but you never know what strange political alliances can crop up."

William Hill has Tony and Gale, Cherie Blair's mother's name, as 8-1 favourites.

But there are also short odds on a Scottish name like those of their children Euan, Nicky and Kathryn.

Boys' names include Ian at 9-1, Alistair and Alex at 12-1 and Calum on 16-1, while for the girls it is Fiona and Olwen at 10-1, Chloe at 12-1 and Victoria at 14-1.

Gordon, after chancellor Gordon Brown, and Keir, for the first Labour party chairman Keir Hardie, both 25-1.

The rank outsiders at 1,000-1 each are Lionel and Clair.