Christine's conviction for perjury was unjust

 On the night of the assault, Witnesses Rudolph “Truello” Fenton and Clarence Camacchio, put Christine under pressure not to involve them. One was married, one had already been in trouble with the police, both were West Indian and afraid of the police.

Christine lied and did not tell the police they were there, she later said in court and said they were not there.
This was deemed enough to charge her with perjury.

Christine Keeler was so hated in the eyes of the public, she was advised that if she did not plead guilty, she would lose and go to prison for 5 years

She took a deal to serve less time and to have some charges dropped, charges that would have allowed Lucky Gordon to sue her for wrongful arrest, for a crime it was accepted, that he had committed. 

Her denial of Fenton and Camacchio's presence was wholly immaterial to the fact that Gordon assaulted her, If she had said they were the in court, there would have been the same outcome for Gordon. It was a lie without any malice. 

She was not lying about an innocent man, he had assaulted her that night.

Imagine your house is robbed, the burglar is caught, there are witness, found in possession of your stolen items, and you go to court.
In court you, the victim are asked. “Where were you at the time of the robbery” and you say “I went to the cinema”
The defence then says “We have proof that you were in fact, unbeknown to your family, at a hotel with your lover!”

Image that you end up in prison whilst the burglar goes free.

That is what happened to Christine Keeler