Mohammad Asghar, who claims to have mental illness, was yesterday sentenced to death under the controversial law by a court in the Pakistani garrison city of Rawalpindi.
A fine of Rs 1 million was also imposed on Asghar, who was arrested in 2010 in Rawalpindi for writing letters to several persons in which he claimed to be a prophet.
"Mohammad Asghar is now facing the gallows simply for writing a series of letters. He does not deserve punishment. No one should be charged on the basis of this sort of conduct," said Polly Truscott, Amnesty International's Deputy Asia Pacific Director.
The law undermines "the rule of law, and people facing charges risk death and other harm in detention", she said. Pakistan must immediately release Asghar and reform its blasphemy law, she added.
Also Read
In November 2012, another British citizen, Masud Ahmad, of the Ahmadi sect, was imprisoned for reciting a passage from the Quran, a prohibited act for Ahmadis under the blasphemy law.
Masud was denied bail and his health is deteriorating as he languishes in jail awaiting an appeal of his sentence, Amnesty said.
Truscott further said several individuals had been attacked and some even killed following charges of blasphemy.
The blasphemy law has fostered a climate of religiously-motivated violence, which leads to persecution of religious minorities and Muslims. It is often used to make unfounded malicious accusations to settle personal scores in land and business disputes, Amnesty said.