They made the announcement on Zoe Ball’s Radio 2 Breakfast Show on Tuesday morning, revealing fans will be able to follow their every move on the BBC Red Button when they undertake the challenge on 11 March.
Every show on Radio 2 will also follow their progress across the 24-hour period, as celebrity friends join in to support them.
Claudia said: “I’m so excited to be taking on this epic danceathon challenge with Tess live at Radio 2 in the legendary Wogan House.
“I know it’s going to be hilarious to watch because we’re pretty bad dancers – I’m not very good at standing, let alone dancing.
“Thankfully we’ll have each other and we’re going to push through to raise as much money as we can for Red Nose Day.
“We love Comic Relief and believe in everything they do. We’ve seen first-hand how the money raised provides a lifeline for people living in the most desperate situations, and we’re doing this for them.
“We want people at home to come together, dig deep and support us through this because dancing for over 24 hours is going to be one hell of a challenge.”
Tess added: “I am so proud to be supporting Red Nose Day with Claudia. I just hope we have the stamina to ‘keep dancing’ for over 24 hours straight!
“We were worn out during our first choreography session so it’s no doubt going to be a tough challenge. But we’re doing this to raise money for Red Nose Day, so it will be incredibly special, and we’ll be thinking of all the people that will benefit from all the amazing projects funded by Comic Relief.
“Doing this at Wogan House is extra special for me, having worked with the great man Sir Terry himself many times.”
Tess and Claud are not the first celebs to take part in the challenge, with Dermot O’Leary taking part in a day of dance in 2015. Sara Cox then took it on in 2017, with both of them raising over £2 million for Comic Relief.