Muhammad was the most popular name given to newborn boys in London in 2015, marking the fourth year in a row that the name has topped the chart in the city. It also reclaimed the top spot in the West Midlands, second place in Yorkshire and the Humber, and joint third in the North West.

The name did not feature in the top ten at all in the North East, the East Midlands, the East of England, the South East, the South West or Wales, according to the Office of National Statistics (ONS).

But when combined with alternative spellings such as ‘Mohammed’ it topped the charts in Yorkshire and the Humber – and the country as a whole.

Officially the most popular name given to newborn boys in England and Wales last year was Oliver (bestowed upon 6,941 boys), followed by Jack and then Harry. Muhammad was ranked 12th, with 3,730 boys given the name.

But when combined with alternate spellings ‘Mohammad’ (ranked 29), ‘Mohammed’ (ranked 68), and ‘Muhammed’ (ranked 121) the name rises to the top of the charts, given to 7,570 boys.

Controversy has raged during the last few years over whether the names should be combined in this way, with critics pointing out that Oliver and Ollie (ranked 77, given to 873 boys) are also listed separately. However, the variations on Mohammed this year outnumber Oliver and Ollie combined.

And while Oliver and Ollie are often considered to be different names, akin to Kate and Katherine, scholars have highlighted that the various spellings of Mohammed occur because the name is transliterated from Arabic.

Ibrahim Othman, an Arabic teacher at the Arab British Centre, said the variations would be comparable to Jon and John, but not Oliver and Ollie as the latter is a shortened version and therefore a separate rendering.

“They [Mohammed variants] are the same name but it’s up to people how they want to spell it,” he told The Independent.

“There’s no difference, it’s just because some people would say an ‘o’ or a ‘u’ more accurately represents the Arabic.”

The name, meaning “praised” or “praiser of God” is one of the most popular names worldwide, leading to some people shortening it or using it as a middle name.

“It’s religious – it comes down to a praise of Mohammad that can be followed by other names that combine to construct a praise of the Prophet,” Mr Othman said.

The ONS, which lists all names as they appear on official documents, has said it will stick to the policy of listing all spelling variants separately.

“To make a fair comparison either all names should be treated separately or all names on the list should be combined with names that have a similar spelling,” a spokesperson said.

“If the latter approach was taken it would make the lists look very different. But it would also require subjective decision-making about whether certain names are distinctive or not – for example it would raise issues such as whether or not we should combine Sara with Sarah and Anna with Ana – some people pronounce these names the same way, but other people do not.”