Asia Bibi, the Pakistani Christian sentenced to death for blasphemy, will take her appeal to the Supreme Court, her lawyer has confirmed.

Naeem Shakir told CNN that Bibi's case is "very strong" and he has high hopes that she will be acquitted.

"I am sure the Supreme Court will provide us with relief. There is no concrete evidence against Asia Bibi, and the courts are only relying on the statement on those two women," he said on Monday.

A Pakistan Analyst for Christian Solidarity Worldwide (CSW) last week told Christian Today that it is "highly unlikely" that Bibi's sentence, which was upheld in the Lahore high court on October 16, will be carried out.

"She is the first Christian woman to ever be handed the death sentence, and Pakistan haven't carried out any executions in six years," the source, who could not be named for security reasons, added.

"No one has ever been upheld on a blasphemy charge in the Supreme Court....If there is any hope of Asia getting justice it's through the Supreme Court."

Found guilty of blasphemy in November 2010, Bibi has been on death row for almost four years. Her lawyers will now take her case to the upper echelons of the Pakistani legal system.

However, a representative from persecution charity Release International warned that should she walk free, "extremists will be given encouragement to pursue their own line of assassination...So both Asia and her family are at risk, whatever the law decides to do."

Shakir has confirmed that he himself feels "threatened" by those calling for Bibi to be hanged.

"Even in the court, there were some two dozen people who were against Asia Bibi. I have not received any threats literally, but the presence of people there makes the environment very hostile toward us," he said.

Two people associated with Bibi's defence have been assassinated. Governor of Punjab, Salmaan Taseer, was murdered by a member of his security team in January 2011 for opposing the blasphemy laws.

Minority Affairs Minister Shahbaz Bhatti, the only Christian member of Pakistan's cabinet, was shot dead by gunmen who ambushed his car in March 2011. He had spoken in defence of Bibi, and said he was "committed to the principle of justice for the people of Pakistan."

"There is a move to harden up the law, and it's becoming difficult to speak up in Pakistan," Release's Andrew Boyd said.

"The Federal Sharia Court of Pakistan has called for a mandatory death sentence for blasphemy, so there's a clear shift in direction of hard-line thinking taking place in the country."