A Conservative MP has said the death penalty is the "proper punishment" for some serious crimes.
Andrew Turner said a full Parliamentary debate should take place about whether it should be brought back for those who killed children or police officers.
His comments come after Leicestershire Police Authority member and Labour councillor Barbara Potter said she believed in "an eye for an eye".
Amnesty International called the death penalty "a cruel relic of the past".
Mr Turner said he was timing his comments with the recent launch of a government petition website enabling the public to initiate parliamentary proceedings.
Campaigners who secure at least 100,000 signatures will be eligible to have their ideas debated in the House of Commons.
The government will begin publishing the petitions for signing on 4 August but people can already create them.
Mr Turner said he was backing a petition by right-wing political blogger Paul Staines - who writes the Guido Fawkes blog - for a review into "all treaties and international commitments which may inhibit the ability of Parliament to restore capital punishment".
Mr Turner, who represents the Isle of Wight, said in a statement he thought it was "high time that this issue is debated".
"My instinct is that some crimes are so horrific that the proper punishment is the death penalty," he said.
"A few people commit acts so evil they are beyond understanding, for example Ian Brady, the Moors murderer; Roy Whiting who abducted and killed eight-year-old Sarah Payne and, more recently, those who tortured and were then responsible for the death of Baby P, Peter Connolly.
"Like many people I have concerns about the possibility of wrongful convictions, so perhaps we should consider whether before a death sentence could be passed, a higher standard of evidence would be needed than 'beyond reasonable doubt' which is used to secure a criminal conviction.
"Some people have suggested that there should be proof 'beyond the shadow of a doubt' before a death sentence could be passed."
Amnesty's UK head of policy and government affairs, Jeremy Croft, said: "In our experience public support for capital punishment falls dramatically when people are confronted with the grim reality of what it means to put a person on trial for their life and then kill them."
He said concerns remained about miscarriages of justice, such as the Birmingham Six, the Guildford Four, or Stephen Downing and Barry George.
Leicester city councillor Barbara Potter, who represents Humberstone and Hamilton, recently joined the Leicestershire Police Authority.
She said: "I'm a mother myself, so I want to keep them as safe as possible. I believe in an eye for an eye, a tooth for a tooth and a life for a life.
"With all the DNA technology we can be 100% sure that someone is guilty and when we are 100% sure that this man has killed this child and the evidence is there, then capital punishment is appropriate."
- 28 July 2011