indesit WIL143S knocking when starting and finishing spin?

I bought the WIL143S Indesit washing machine 5 years ago and up until now it has been fine. It is on a level floor and set up correctly, but recently when on woolens cycle 6 and going onto spin and coming off spin, there is a severe knocking noise and increased movement when looking at the drum. The machine then decides to walk across the kitchen floor. an anyone help please?