Anger as Ahmadinejad delivers Christmas message on Channel 4

The speech by the president is not scheduled at the same time as the Queen's Speech on BBC and ITV as in previous years but will go out at 7.15pm.

Campaign groups attacked the broadcaster's decision to air the speech, as "dangerous" and motivated by ratings.

However, the president uses the message to express his wish for a peaceful New Year and greater spirituality among governments, leaders and society as a whole.

Speaking in Farsi with English subtitles he will say: "Jesus, the Son of Mary, is the standard bearer of justice, of love for our fellow human beings, of the fight against tyranny, discrimination and injustice.

"If Christ were on earth today, undoubtedly He would stand with the people in opposition to bullying, ill-tempered and expansionist powers.

"If Christ were on earth today, undoubtedly He would hoist the banner of justice and love for humanity to oppose warmongers, occupiers, terrorists and bullies the world over.

"If Christ were on earth today, undoubtedly He would fight against the tyrannical policies of prevailing global economic and political systems, as He did in His lifetime."

But the Israeli Embassy branded the Christmas message a "sick and twisted irony".

Israeli Ambassador Ron Prosor said: "In Iran, converts to Christianity face the death penalty. It is perverse that this despot is allowed to speculate on the views of Jesus, while his government leads Christ's followers to the gallows."

He said Channel 4's decision to broadcast the message was a "scandal and a national embarrassment" and in "its search for ratings and shock factor, Channel 4 has lost its ethical way".

Human rights campaigner Peter Tatchell joined the attack, and called on the broadcaster to "pull the plug on this criminal despot, who ranks with Robert Mugabe, Omar al-Bashir of Sudan and the Burmese military junta as one of the world's most bloody tyrants".

Stephen Smith, director of the Holocaust Centre, said the message should be treated with caution.

President Ahmadinejad's views on the state of Israel and his claims that the Holocaust is a "myth" have angered Jewish groups.

Mr Smith said: "I think this benign message is deceptive. People need to be alert to the fact that this is a wolf in sheep's clothing.

"Many of his political and historical views are very dangerous and do not uphold the views in his message."

Mr Smith criticised "the fact that somebody who openly denies the Holocaust is given legitimacy on prime-time television, someone who uses Holocaust denial to be divisive".

Rabbi Aaron Goldstein, of Liberal Judaism, said: "I have no trouble with Channel 4 dealing with difficult issues. The Queen's speech is so benign that it is worthwhile having something thought-provoking.

"But doing a sort of lucky dip to pick out a controversial character, then allowing him to make a lovey-dovey speech, that this character is being allowed to dress himself up as a kind of Father Christmas, that is problematic."

However, Channel 4 received support from Ben Summerskill, director of gay rights group Stonewall.

He said: "In spite of his ridiculous and often offensive views, it is an important way of reminding him that there are some countries where free speech is not repressed.

"If it serves that purpose, then Channel 4 will have done a significant public service."

This is not the first time the channel has courted controversy with its choice of speaker. In 2006 a fully-veiled British-born Muslim woman used the message to attack Jack Straw for his criticism of the niqab (face veil) earlier the same year.

It is the broadcaster's 16th alternative message since Quentin Crisp delivered the first in 1993.

Channel 4 head of news and current affairs Dorothy Byrne defended the decision to broadcast tonight's message.

She said: "As the leader of one of the most powerful states in the Middle East, President Ahmadinejad's views are enormously influential.

"As we approach a critical time in international relations, we are offering our viewers an insight into an alternative world view.

"Channel 4 has devoted more airtime to examining Iran than any other broadcaster and this message continues a long tradition of offering a different perspective on the world around us."