A balaclava-clad thug who bludgeoned a post officer worker on her head with a hammer in a "sickeningly violent" attack has been jailed for nearly seven years.

Daryl McNamee, 28, was sentenced today at Inner London Crown Court after the attempted robbery at the sub post office in Valley Drive.

He was sentenced to six years and eight months after pleading guilty to attempted robbery and three years for ABH, to run concurrently.

Video: The moment vicious thug McNamee raids a post office in "sickening" attack

McNamee, of Jenningtree Road, Erith, burst into the shop clad in a boiler suit, gloves and balaclava with two accomplices in July 2013, during the middle of the afternoon.

The victim, who was in her 60s, was grabbed around the neck before being struck twice with a claw hammer, leaving her partially unconscious.

As another man attempted to smash a glass partition where the Postmistress was working, McNamee tried to force the till open but failed.

McNamee then ripped it from the counter and dropped it on the victim lying at his feet. Fortunately, a chair blocked the till from landing on the victim’s head.

A third man acted as a lookout.

The three men ran out empty-handed and made their getaway in an Audi A3 which had been stolen from a burglary in Blackfen, London.

McNamee was arrested when police found gloves matching his DNA in an abandoned Audi, which was used as a getaway vehicle.

Glass fragments also found in the car matched those in the door of the post office.

With this evidence, McNamee was later charged with the offence.

In January, he appeared at Inner London Crown Court where he pleaded guilty to the attempted robbery and assault.

Investigating officer, Detective Constable Paul Walker of the Kent and Essex Serious Crime Directorate, said: "This was a sickeningly violent and gratuitous attack on a woman in her 60s who was just trying to do her job.

"McNamee showed no mercy towards her, even attempting to drop the heavy till on her head as she lay semi-conscious at his feet.

"It does not bear thinking about the sort of damage that could have done had his aim not have been blocked by the wooden stool.

"Such was the unprecedented violence used that we aired the footage of the attack on the BBC’s Crimewatch and received a number of calls from the public to assist us in the investigation.

"We also worked closely with our colleagues from the Metropolitan Police in order to piece all the available evidence together and unmask the attacker.

"The victim of this frenzied assault has been left picking up the pieces and is still unable to return to work.

"I have absolutely no doubt that McNamee poses a danger to the public and welcome the news today that he will be behind bars for the foreseeable future" - DC Paul Walker

"I would like to pay tribute to her fortitude in assisting us with this investigation and hope McNamee's sentence allows her some closure on her ordeal.

"I have absolutely no doubt that McNamee poses a danger to the public and welcome the news today that he will be behind bars for the foreseeable future.

"However, today does not mark the end of this investigation. We will continue to work to bring to justice the other men responsible for this heinous attack and I would encourage anybody with information to contact the police or Crimestoppers."

Anybody with information on the incident is asked to call 01474 330519, quoting XY/20245/13.

Alternatively, to remain anonymous, call Kent Crimestoppers on 0800 555111.