The sons of a woman who killed her husband in a hammer attack have launched a public appeal for her murder charge to be downgraded and have accused the CPS of “discrimination against women”.

Sally Challen, 65, was jailed for life for the murder of her husband, Richard, 61, after a trial at Guildford Crown Court.

Last week, in a landmark case at the Court of Appeal in London, her conviction was quashed and a retrial ordered.

The court ruled that evidence she was suffering from two mental disorders at the time of the killing undermined the safety of her conviction. The Crown Prosecution Service (CPS) has 28 days to formally reindict Mrs Challen for murder.

Now her sons, David, 31, and James, 35, are launching an appeal for the CPS to drop the murder charge, saying that violent men are “often offered reduced pleas”.