Kate Moss is said to have warned Rhys Ifans that rumoured girlfriend Sienna Miller is bad news.

Kate is convinced that her rival will break close pal Rhys’ heart – and has reportedly not shied away from telling the Welsh actor so.

A designer friend of Sienna's told Britain's Daily Express newspaper: "Kate isn't happy. Rhys was her main male friend in her close-knit group. She isn't keen on Sienna. There is definite tension between them.

"Sienna was fuming after Kate gave Rhys a talking to when she heard the relationship was getting serious. Kate doesn't think it will last and doesn't want Rhys getting hurt."

Kate is said to have accused Sienna of stealing her style and her friends during a blazing row at a wedding last month.

So she won’t be thrilled to hear that – despite still denying they are a couple – Sienna and Rhys (Rhienna?) are so in love they are even considering getting married.

The source continued: "Sienna is probably the happiest I've ever seen her. She and Rhys are perfect together.

"They are having such a great time, I wouldn't be surprised if they got engaged."

To see pictures of Sienna and Rhys whacky weekend, click here!