A thug who politely asked to borrow a knife used to cut a birthday cake at a party and then slit a man’s throat has been locked up indefinitely with no hope of release for at least 14 years.

Sean McLaren had calmly walked up to Gillian Ballard after she used the knife for her 60th birthday cake and carried out what a judge said was "akin to a public execution" in front of shocked guests.

Victim Brett Banks narrowly escaped death as the blade just missed his jugular vein. He bled profusely and was left with an unsightly 10cm scar across his neck.

McLaren was to boast to police: "I am proud of what I did. I am gutted I didn’t kill him."

Judge James O’Mahony told the 37-year-old: "I cannot conclude this was, drink or no drink, not a deliberate and cooly executed attempted murder in public in a deliberately shocking, cruel manner verging on a sadistic act."

Maidstone Crown Court heard that the horrific incident happened on March 1 at the Rochester Queen floating restaurant, moored on the River Medway at Cuxton.

Philip St John-Stevens, prosecuting, said McLaren had asked "in a friendly manner" if he could borrow the knife used to cut the cake.

Without saying a word, he casually walked up to father-of-two Mr Banks, pulled back his head and drew the blade across his neck.

"He felt a sensation of coldness and then profuse bleeding," said the prosecutor. "Onlookers went to his assistance. The defendant left the scene.

"An ambulance was called. The wound was about 10cm in length. Doctors implied if it was any deeper, it would have been fatal."

Police went to McLaren’s home within 90 minutes and arrested him. He chillingly told officers: "Is this about the knife? Is he dead? He deals in drugs. I hope he is dead."

He later admitted his claims were false. He said he had drunk up to nine pints of Stella lager. He could not remember what he had done but knew it was "something bad".

His father had warned him not to drink strong lager because it made him aggressive.

Known as Starkie, McLaren, of Cuxton, admitted attempted murder.