Mr Osman’s debut novel, The Thursday Murder Club, sold 134,500 copies in the week up to Saturday, more than double the former US president’s 66,500 sales. It is the first debut novel to top the Christmas sales charts.

Mr Obama’s A Promised Land is the first volume of a two-part memoir, released last month, and has sold more than three million copies.

It is closing in on Bill Clinton’s ‘My Life’ and George W Bush’s ‘Decision Points’, which have sold 3.3million and four million copies respectively.

If it passes their tallies it will become the best-selling presidential memoir of modern times.

Mr Osman tweeted: “Well this is just the most wonderful news. #TheThursdayMurderClub is Christmas number 1. I’m absolutely overwhelmed. Thank you all so much. Merry Christmas.”

His murder mystery has sold almost 700,000 copies in less than four months and has attracted the attention of Steven Spielberg.

The presenter said he was “thrilled” that the iconic filmmaker, 73, was interested in adapting the novel.

He told Good Morning Britain: “Spielberg is the greatest film director of all.

“I’m the guy who made Total Wipeout and Deal or No Deal, he’s the guy who made Jaws.”

Describing the plot, Mr Osman said: “It’s about four people in their seventies.

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It was published by Crown Publishing Group on November 17.

Mr Obama has many reasons to celebrate as it was named The New York Times bestseller on December 20.

It also placed on end-of-year best of lists by The New York Times, The Washington Post and The Guardian.

No release date has been set for the second book.

It follows his 1995 memoir, Dreams from My Father, and his 2006 work Audacity of Hope, which became a New York Times and Amazon bestseller.

Wife Michelle’s book, Becoming, has sold more than 14 million copies worldwide.