Worboys was convicted of the offences of one rape, five sexual assaults and 12 charges of drugging women, although a further 75 victims made complaints against him. 

Keir Starmer was then Director of Public Prosecutions as the department took the decision not to prosecute the London cab driver, who is now 60, after he was awarded a life sentence. 

He came under increasing pressure last night on social media to break his silence over the case and justify his stance. 

Sir Keir’s Labour party colleague Yvette Cooper last night tweeted her concerns over the decision to allow Worboys to be released from jail after serving just 10 years.  

She tweeted: “Really shocked by this. 

“His were the most appalling & vile crimes. 

“Very serious questions about this decision.” 

But former senior investigating officer for the Met Police Murder squad Colin Sutton, who lead more than 30 successful murder investigations including the Levi Bellfield case in a tweet to Ms Cooper said: “It might have made a difference if CPS had prosecuted more of his known crimes.  

“Perhaps you can ask Keir Starmer why he didn’t. 

“There were in excess of 70 known in 2009 when his trial ended.” 

But shadow Brexit minister Sir Keir said nothing in light of the criticism on Thursday and the Department of Public Prosecutions said the Labour MP did not comment on his time within the department.