Friends of newly engaged couple Liz Hurley and Shane Warne have expressed concerns about their future together.

The couple got engaged over the weekend at the Old Course Hotel in St Andrews, the Daily Mail reported.

A source told the tabloid: “Shane proposed over dinner and it was fairly public, not a private affair. It was a VIP crowd in there this evening. It was residents only, including Dunhill past players."

“He didn’t get down on one knee, but when it was announced the other guests in the restaurant stood up and applauded. Everyone there was absolutely delighted.”

But the speed of the couple's 10 month courtship has raised eyebrows amongst their mates.

 “A lot of us are very surprised – and a bit concerned for Liz.” One chum confessed to the Daily Mail.  “What started out as a fling has become something far more. They seem to have got caught up in the moment.”

“However much chemistry there is between Shane and Liz, they are from very different worlds. She is very much part of upper-crust society, and he is a Jack-the-lad Aussie.”

The ex-cricketer and actress became an item after meeting at a race meeting in July last year.

Warne drops 2 stone – Is Hurley behind it?

Since dating Hurley, Warne has been transformed into a sleek, groomed metrosexual and has lost his trademark beer belly.

Mother of one Hurley, 46, recently divorced businessman Arun Nayar after four years of marriage while Warne, 42, has three children with ex-wife Simone.

Since their engagement, Hurley has been sporting a huge rock on her ring finger.

Bookmaker William Hill is giving odds of 3-1 that Hurley and Warne will break off their engagement. (That's not very nice!)