The first edition of French satirical magazine Charlie Hebdo since the massacre which left 12 people dead has been revealed - with its front cover depicting a cartoon of the Prophet Mohammed.

Up to three million copies are believed to have been printed ahead of tomorrow's publication date - well up from its usual run of 60,000 - with reports of 1,000 copies being made available to British retailers.

French newspaper Liberation published the latest Charlie Hebdo front cover online ahead of the satirical magazine's publication. It appears to show the Prophet Mohammed against a green background with a tear streaming down his cheek, holding a sign reading "Je suis Charlie", replicating the phrase meaning "I am Charlie" which was used as a show of unity in the wake of the attacks.

The headline carries the phrase "Tout est Pardonne" (All is Forgiven), which French media have interpreted to mean Mohammed is forgiving the cartoonists for lampooning him. It will be the biggest print run in the magazine's history, French press said.

Fundamentalist brothers Said and Cherif Kouachi were responsible for the attack on Charlie Hebdo's Paris offices last Wednesday, as staff held their editorial meeting for the forthcoming edition, which was believed to have an Islamic theme.

Cartoonists, journalists and police officers were among those gunned down by the brothers before they were shot dead by armed police following a stand-off at a printing works north of the capital on Friday afternoon.

Deputy Prime Minister Nick Clegg defended the cover as part of an "ideological struggle" to maintain a free society and suggested he could be among those snapping up a copy of the magazine.

"I'm not sure I'm going to buy it but I would defend the right to publish a cover like that.

"I might buy it but whether I buy it or not is not really the issue - the issue is do we live in a society where people can publish things on the covers of their magazines or their newspapers which may be offensive to some parts of society but where we nonetheless defend the right to offend.

"What is at stake, above and beyond the immediate physical threat to the safety of those who were killed and maimed in Paris and indeed the ongoing physical threat to us in this country, there is also an ideological conflict going on between those of us in our society who believe in openness ... and those who want to close societies.

"I don't think you can have freedom unless you are also free to offend each other in an open society.

"One of the great dilemmas we face is how do people retain their own identities but not seek to impose their identity on other groups and other individuals who they share society with."

Broadcasters and publishers were this morning faced with the decision whether or not to replicate tomorrow's controversial Charlie Hebdo cover.

The Guardian was among those to carry the front page on its website, while the Telegraph.co.uk cropped part of the design to remove the depiction of Islam's holiest prophet.

Plenty of others chose not to repeat the image.

In a blog post on the Associated Press (AP) website, the news agency said it had previously taken the decision not to run Charlie Hebdo cartoons mocking Islam.

It said: " AP tries hard not to be a conveyor belt for images and actions aimed at mocking or provoking people on the basis of religion, race or sexual orientation. We did not run the Danish cartoons mocking Muhammad in 2005, or the Charlie Hebdo cartoons of the same type.

"While we run many photos that are politically or socially provocative, there are areas verging on hate speech and actions where we feel it is right to be cautious.

"This policy is consistent with our approach to sound bites and text reporting, where we avoid racist, religious and sexual slurs."

London Mayor Boris Johnson said Charlie Hebdo had "no choice" but to print the cover it had, following the unity marches in France and defences of press freedoms in the wake of the attacks.

He told the BBC Radio 4 Today programme: "You cannot have a march through the streets of Paris attended by 46 world leaders, four million people, climaxing with a shout of 'We are not afraid' and then not print the central object of contention.

"Of course they are right to do that and I am afraid it is absolutely vital now that everybody stands up and defends their right to publish.

"You may not agree with what they have done, you may be offended by what they have done, but you should defend their right to publish it."

A spokeswoman for UK newspaper and magazine wholesaler Smiths News said: "We are due to get a very limited supply of the title but full details are yet to be confirmed."

She said she could provide no further information as details have to be agreed, but said that yesterday she had heard talk of about 1,000 copies.

On its website, Smiths News said it distributes "a diverse range of print media to 30,000 customers, ranging from large general retailers to smaller independent newsagents".

A spokesman for Comag said the firm will be involved in the distribution of the magazine but he did not know how many copies it would be handling, adding: "It's not going to be a lot, to be honest."

He said some customers would want more but he did not think the company would "be able to satisfy that".

He added that customers interested in receiving the magazine are "specialist retailers, not newsagents".

The spokesman said no-one at the firm had indicated any worries about security, adding: "We're here to serve our customers. If our customers are requesting it then it's our job to service that."

An employee at Menzies Distribution Ltd confirmed it will also be involved in the distribution of the latest issue of Charlie Hebdo and said they have taken orders for the magazine from customers.

A spokesman for Menzies Distribution said: " I can confirm that Menzies Distribution will handle supplies of the upcoming Charlie Hebdo special edition.

"We don't expect to face particular security issues, but we will take whatever precautions our security team believe are sensible to ensure the safety of our employees.

"As the allocation process is still ongoing - and we don't know for certain our supply from the distributor - I'm unable to comment on the type of customers likely to receive copies."

Sky News was among those ruling out broadcasting the Charlie Hebdo cover. A spokesman said: "Sky News has given extensive coverage to this story and to the highly controversial issues surrounding it, which have been debated on TV and across our other platforms on numerous occasions over the last few days.

"As with any controversial story, the issue of publication of the cartoons has been subject to rigorous editorial scrutiny and discussions - which will continue.

"Currently, Sky News will not be broadcasting these images on any of its platforms."