The special comes following a report claiming that ITV has axed regular editions of Chris Tarrant's quiz show in favour of the live specials. The first, broadcast last December, was a ratings hit.
EastEnders actress Palmer will be partnered by her eldest son Charley and play to raise money for CLIC Sargent, a leading UK children's cancer charity. Walliams and his mother Kathleen will be attempting to win the million pounds on offer for The Princess Alice Hospital, while Murs will be joined by his mother Vicky to raise money for Brainwave.
One viewer will also stand the chance of winning half of the total earned by one of the pairs.
Murs said: "I can't wait to go on Who Wants To Be A Millionaire? with my mum. I have no idea how much money we will make but I'm sure it's going to be a good laugh and I've got my fingers crossed that we raise lots of money for charity."
Live Celebrity Who Wants to Be a Millionaire?: Mother's Day Special will air on ITV1 at 8.25pm on Saturday, April 2.
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