Louise Plowright is to take over the lead role in the smash hit stage show Mamma Mia! She will replace former Evita star Siobhan McCarthy from March 20 and will be joined by West End newcomers Julie Atherton (Donna) and Gareth Bryn (Sky) who will take over from the show's golden couple, Lisa Stokke and Andrew Langtree. Mamma Mia! recouped its original production costs in a record-breaking 27 weeks, and is currently booking up to March 17 next year - with a box office advance of £8 million.