George Galloway, the former British Labour Party MP, one-time Celebrity Big Brother contestant, Saddam Hussein apologist and notorious cat imitator, has announced that he is about to enter the next phase in his destiny as a man hurtling towards the twilight of his time in the public eye, by writing a children's book.

Galloway says he has signed a deal for the first book in a series, Red Molucca the Good Pirate, about "a husband and father whose family (and dog) pirate alongside him. A kind of Robin Hood of the high seas."

No details about the identity of the publisher are forthcoming yet.

On BBC radio the award-winning author of A Monster Calls, Patrick Ness, had some advice for Galloway, warning him that "writing for children cannot be an act of vanity. A successful children's story does not broadcast, it does not preach. It interacts, it asks, it respects." He added, "It's not the subject matter that bothers me. It's the dilettantism, as if writing for children was so easy anyone could do it."

Galloway responded on Twitter by indicating that he did not know who Ness was.

“Who he?” he tweeted at the BBC.

It is a little worrying that Galloway is not aware of the identity of one of the most acclaimed practitioners of the craft he is now attempting to emulate. But, leaving that aside, perhaps we should give him a chance.

If his book does eventually see the light of day he won’t be the first politician or celebrity to have attempted to reinvent himself as a children’s author.

Political figures who have previously turned their hands to writing for children include the former US presidents Barack Obama and Jimmy Carter, the former Australian prime minister Kevin Rudd and the former British minister Norman Tebbit. Other celebrities who have rebranded themselves, briefly, as children's authors include Madonna, Katie Price, Geri Halliwell, Kylie Minogue, Ricky Gervais, Will Smith, Coleen McLoughlin and Sarah Ferguson.

As the outcome of certain of these endeavours has demonstrated, "short" and "for children" does not mean "easy", according to Sarah Webb, author and curator of the children's programme at the Dún Laoghaire Mountains to Sea book festival. "Picture books are the hardest of all forms of children's literature to write. It really bothers me when celebrities go into the children's-book market just because they think, Well, they're short, anyone can do this. I call picture books 'haiku for aliens'. In 500 words or less, it has to have a full story, full characters, full plot, and it has to appeal to children and adults – and that demands exceptional talent. When it works it's wonderful."

There are, however, celebrities who have made the transition into the genre with considerably more success than, for example, Madonna.

"Whether or not it's a success depends very much on the person," Webb says. "I'm delighted whenever I hear that a celebrity who has a genuine interest in children and in writing says they're going to write a children's book. David Walliams and Julian Clary are examples. I'll admit I was a bit nervous reading Clary's first book, The Bolds, but it's a fantastic story."

Paul Black, who's currently on a book tour with Clary, is a publicist who has worked with both Walliams and David Baddiel, who recently won a Laugh Out Loud, or Lollie, award for his book The Parent Agency. So what does he think are the winning ingredients of a children's book?

“Above all it needs to be a great story – be it funny, be it adventurous, be it full of heart. Children will respond to a message, but it shouldn’t be too front and centre,” he says.

Clary, Walliams and Baddiel work because “they’re funny – they come from comedy, and they use that storytelling to great success. Storytelling is stand-up in a book form. If you’re a comedian you know how to please an audience, be that an adult or a child – and there can be few tougher or more discerning audiences than a crowd of eight-year-olds.”

Elaina Ryan, the director of Children’s Books Ireland, says the same elements that make any book a success also apply.

“Excellent writing, a credible voice and an original idea might make up the winning formula, but in terms of commercial success there’s also the uncontrollable element of luck and the very varied issue of the marketing budget that goes behind a book,” she says.

But before he gets to that point George Galloway could do worse than reading these hits and misses in the celebrity children’s books literary genre.

The Hits

The Bolds by Julian Clary (2015): "It's a great story, it's very inclusive and it's very funny. It's all about a family of hyenas who are passing themselves off as someone else. The funniest bits are when they don't rein themselves in. So it's got a great message about being yourself, and you can hear Julian Clary's voice in it when you're reading," the author and curator Sarah Webb says.

The Midnight Gang by David Walliams (2016): The comedian, who has sold more than 12.5 million books and been translated into 46 languages, is rarely off the bestseller lists, and this latest title continues that run. His writing style has, with some justification, often been compared to Roald Dahl's. Claire Hennessy wrote in The Irish Times that "The Midnight Gang, which begins in the children's ward of a hospital, also touches on more serious themes (without getting too solemn). It may be his best yet."

One to watch out for in 2017 is Yoga Babies by Fearne Cotton: "It is coming out in September. It's a fab picture book for younger readers. Fearne has written the text herself, and it very much comes from her heart," says the publicist Paul Black.

The Misses

Five Books for Children by Madonna (2005): "They were pretty dreadful. I can barely remember them, to be honest. I didn't think the story was very good, and she went a bit too hard on the Kabbalistic messaging," says Paul Black. Sarah Webb agrees: "Although she's a songwriter of great talent, she hadn't written fiction before. Her books have no real substance or real heart."

Budgie the Little Helicopter by Sarah Ferguson (1989): Critics were quick to scoff at this abduction-themed story, and recent Amazon reviewers reveal that more contemporary audiences remain unconvinced. "There is some strange innuendo between Budgie and Pippa. There seems to be something a little off or weird about the Budgie stories I can't quite put my finger on," writes one. Undaunted, Fox Children's Network paid £800,000 for the US TV rights, helping to secure the duchess of York's financial future.

The Perfect Ponies by Katie Price (2007): There was uproar when the model's ghostwritten "masterpiece of equine elegaics", as the Guardian calls it, was nominated for a literary award, in 2007. "The dialogue doesn't sparkle ('I get well thirsty grooming') and the characters are chiefly distinguished by their hair-dos, giving it the feel of something written by committee. This is a great shame, because Price is a keen, knowledgeable horsewoman," lamented the Telegraph.

Julian Clary will be at the Pavilion Theatre in Dún Laoghaire at noon on Saturday, March 25th, as part of the Mountains to Sea book festival