A woman has been jailed for life with a minimum term of 22 years after admitting the frenzied stabbing of her sister, with whose husband she was having an affair.

Sabah Khan, 27, stabbed her 34-year-old sister Saima 68 times after luring her home on the night of 23 May 2016, while their parents and Saima’s husband were at a funeral.

As Saima’s four children lay in their beds, Sabah plunged a knife all the way through their mother’s neck and arms seconds after she arrived in the hallway of their home in Luton.

The court heard how in the midst of the attack Saima’s daughter called out to ask Sabah whether she was killing their mum, and she replied telling them not to come downstairs.

Sabah Khan stabbed her 34-year-old sister Saima 68 times

Sabah then smashed a downstairs window and concealed the freshly purchased murder weapon and her clothes in bin liners before calling her parents and police, to whom she claimed at first that her sister had been the victim of a burglary gone wrong.

Sabah on Tuesday pleaded guilty to murder in a brief hearing at the Old Bailey. The same court heard on Thursday how she had grown increasingly desperate after a longstanding affair with her sister’s husband, Hafeez Rahman, had turned sour.

 Saima Khan was found with 68 different injuries

In WhatsApp messages between Sabah and Rahman read out in court, the defendant referred to her sister as a “bitch” and accused Rahman of marrying her solely for the purpose of obtaining a passport.

One message from Sabah to Hafeez said: “Nothing in the world can change my feelings for you, not even you; no matter how bad you treat me it won’t change anything. Day by day my love gets stronger.”

“She killed her sister because she was bitter and jealous of her sister’s life,” he said. “She wanted her life, her husband and her children. Rather than that she’s spending a long time in prison.”

Defending, Jo Sidhu QC said Sabah Khan had written a letter in which she expressed “failure, guilt, responsibility and shame” for what she had done. He added that she had also had an abortion after getting pregnant with Mr Rehman’s child.

Mr Rehman’s statement added: “I have four beautiful children but I have lost my world and I cry every day. Saima was there for all four children. She did everything.