A former imam, or mosque leader, has warned that extremists are aiming to establish Muslim Sharia law in the UK - and that Britain has become the world "number one target" for Islamic strategists.

Persecution watchdog Release International said that "Sharia law - strict Islamic law - is gaining ground in many nations, resulting in a challenge to basic human freedoms."

A statement released by the organisation explains: "In Pakistan a bill that would impose the death penalty on any Muslim man who changes his faith has passed its first reading. A Muslim woman who converted to another faith would face life imprisonment."

Sam Solomon, a former imam and Islamic lawyer now living in the West, has raised concerns of "creeping" Islamisation in the UK. He has written a special report on Islam in the latest edition of Witness magazine, published by Release International.

He writes: "The UK is the number one target of Islamic strategies in the West (because) the former British Empire controlled some of the largest Muslim communities. Immigrants from these countries... have taken full advantage of Britain's liberal politics."

The news has come as British Prime Minister Gordon Brown said Wednesday his Government would consult on new counter-terrorism measures to ensure suspects are successfully prosecuted.

"The home secretary plans to consult -- and we are seeking an all party consensus on new measures to ensure successful prosecutions against terrorist suspects," Brown told Parliament, without giving further details.

He said he would also consider the case for an extension of the 28-day limit on pre-charge detention for terrorism suspects and on the use of intercept evidence in court.

Ex-imam Sam Solomon, however, has raised concerns that the militants' aim is to establish Sharia law in the UK, applying first to Muslim communities, then extending to the entire population.

"It would be a huge mistake to say that Islam is just another religion like Judaism or Christianity," he writes.

"Islam is a whole system: a social, political, religious, economical, educational, legislative, judicial and military system... with regulations that govern every aspect of the lives of its adherents."

Release said that "where Sharia law has been applied in Pakistan, Christians have been accused of blasphemy and girls and women face abduction and forced conversion". In Nigeria, meanwhile, extremists have burnt churches and targeted and killed Christians, the organisation said.

Solomon continued: "From Afghanistan to Algeria, Indonesia to Iran, at best there is the insidious daily obstruction of the rights of Christians by marginalising them to a low citizenship status, especially when it comes to jobs, or a place at university."

A photograph in Release's Witness magazine vividly portrays what can happen. In the image a young woman hides her face as four grim-faced policemen clad in black escort her from her home. Her shame is obvious. Her friends watch anxiously as she is led away to face charges.

The picture, Release explains, is of a woman in Banda Aceh, Indonesia, who has failed to wear an Islamic headscarf.

"The police are Islamic law enforcement officers. Their task is to enforce Sharia law, with its strict rules on dress, alcohol consumption and sexual behaviour," said Release.

Andy Dipper, head of Release International, said: "We receive daily reports of the persecution of Christians in Islamic nations, especially where Sharia law - strict Islamic law - applies.

"We should be concerned about the increase of Islamic influence in our society because we love truth and righteousness and the freedom to worship God - not because we are afraid."

A British judge jailed four men for 40 years each on Wednesday for the 21/7 attempted suicide bombings on London's transport system in a plot he said had clearly been masterminded by al Qaeda. The failed attack came two weeks after 52 people were killed in the 7/7 attacks.

Judge Adrian Fulford said that the four men, Muktah Said Ibrahim, Yassin Hassan Omar, Ramzi Mohammed and Hussein Osman, all Muslims of African origin, were guilty of conspiracy to murder.

Fulford declared he had no doubt their botched attempt to bomb three underground trains and a bus on July 21, 2005, had been directed by Osama bin Laden's group.

The second wave of attacks only failed because, although the detonators fired, the bombs did not explode.

"This was a viable, indeed a very nearly successful, attempt at mass murder," Fulford told the court. "These were not truly isolated events but ... coordinated and connected in that I have no doubt they were part of an al Qaeda inspired and controlled sequence of attacks."

Sentencing them, Fulford ruled they should stay in jail for a minimum of 40 years, the maximum sentence he said he could impose in light of other terrorism cases.

The men looked impassive as the sentences were handed down. As they left the courtroom, Reuters reported that Osman clutched a Koran to his chest.