Giovanna Fletcher has said that she has a "really exciting" list of household name celebrities who have signed up to take part in her fundraiser, which will see them do video calls with fans.
The author's Be My Guest initiative, which she has launched with TV presenter Emma Willis, has already unveiled Olly Murs, Paloma Faith and Melanie C as participants.
The project will allow fans to buy a GBP 5 ticket to be in with a chance of talking to a celebrity who is taking part.
New names will be unveiled each week and Fletcher said they have enough to last up to three months.
Fletcher told the PA news agency: "They are people from all different areas of entertainment, names that everyone would recognise, it is really exciting."
Willis said that she came up with the idea for the project after waking up in the middle of the night to go to the toilet.
She added: "I literally got into bed and I couldn't fall back asleep and I just thought, you know, we have a connection to certain people."
Willis said she and Fletcher thought: "Who do we know and also who has kind of big followings on social platforms so they can help spread the message and spread the love and hopefully bring in a lot of donations for four fantastic charities?"
The project is raising money for the NHS Charities Together, Mind, Refuge and The Trussell Trust charities.
Fletcher said: "There are a load of names that we can tap into and try and rope them into doing something nice and fun for charity in the hope of raising loads of money, and that is essentially how Be My Guest was born."
Names of new celebrities who will be taking part in the fundraiser will be released each week.
Fletcher said that her ideal person to get on a video call would be the Queen, adding: "I like to aim high."
Willis said that she "loves" how people's social lives have adapted to being online.
"I miss human contact and hugs and physically seeing people because I am a big lover of that, but thank God we have this technology whilst this is happening," she said.
"There are people out there who haven't got access to this technology and imagine how they are feeling."
She added: "As much as we are missing all of our loved ones, it is great that we can see their face on the phone."
Tickets for the competition can be bought at bemyguest.org.