A source said: "What started out as quite low-key is now looking more extravagant.

"They are still keen on a beach wedding in Hawaii or Mexico towards the end of the year, but Jen wants it to be more like a massive party and, at the moment, it looks like it could stretch over three days. Half of Hollywood will be there too."

After Aniston showed off her eight-carat emerald-cut diamond for the first time last week, there is now speculation she will break from her usual simple, classic styles when choosing a wedding dress.

A source told Grazia magazine: "The dress is being kept top secret. But now Jen's debuted this massive ring, it's kind of set a precedent so who knows, we could see Jen break from her conservative, simple style and go for a show-stopper of a dress too."