Publicist found guilty of eight charges of indecent assault against women and girls as young as 15 between 1977 and 1985

Celebrity publicist Max Clifford was jailed for eight years on Friday as a judge ordered him to pay a severe price for sexually abusing four teenage women and trivialising his trial with a "contemptuous attitude" that added to his victims' trauma.

Judge Anthony Leonard imposed a sentence more than double than had been expected, partly because of Clifford's attitude during the trial at Southwark crown court, where he was "laughing and shaking his head" in the dock at some of the accusations made against him.

The judge said his conduct had made his victims "extremely upset" and as Clifford listened through a hearing loop from the court dock, Leonard concluded: "I find your behaviour to be quite extraordinary and a further indication that you show no remorse."

Clifford was told that had some of offences been tried under today's law, they would be considered as rape or assault by penetration with a maximum sentence of life imprisonment.

When the judge finished speaking, Clifford removed his hearing loop and turned and smiled at his supporters in the public gallery, most of whom were in tears, before he was led to the court cells and then to Wandsworth prison. His victims, who were in court with friends and family, comforted each other before being led through to the judge's quarters.

The length of the sentence stunned many inside the packed courtroom, with sources close to the trial expecting Clifford to be jailed for between two and three years due to the sentencing guidelines at the time of the offences.

The sentence, of which Clifford, 71, is expected to serve half in prison, seals the fate of a man who had been instrumental in the downfall of a string of public figures through tabloid stories he had sold.

Leonard sentenced Clifford to four and a half years in prison for his abuse of one victim alone – a 15-year-old girl who was left traumatised by a long campaign of sexual abuse. She told the trial she wanted to kill herself after being repeatedly sexually abused by Clifford in 1977.

He would take her for long drives in his yellow Jaguar and wooed her parents with promises to make their daughter the UK version of Jodie Foster, while secretly molesting her and forcing her to perform sex acts on him. In a victim impact statement read to the court, the woman – who was in court to see Clifford jailed – said he left her relying on counselling and ruined her relationship with her husband and her parents, whom she felt she had deceived by not telling them of the abuse.

She said seeing Clifford protest his innocence on television brought back feelings of "intimidation and fear", adding that her trauma was compounded by seeing him refuse to apologise following his conviction.

Clifford became the first public figure to be convicted under Scotland Yard's Operation Yewtree inquiry on Monday, when he was found guilty of eight counts of indecent assault against four girls between 1977 and 1985. He was cleared of two other charges of indecent assault and prosecutors let another charge remain on file.

His convictions lifted the pressure on the Crown Prosecution Service following the recent acquittals of Tory MP Nigel Evans and Coronation Street actor William Roache.

The director of public prosecutions, Alison Saunders, said she was satisfied with the outcome. "A guilty verdict means victims have been abused and for them it's been a long journey," she said. "I was pleased they were believed, so from that perspective it's a vindication."

She added she had written to Clifford's victims asking to meet them and said that, more generally, she felt women in sexual abuse cases had, as witnesses and victims, a raw deal.

Judge Leonard told Clifford on Friday: "These offences may have taken place a long time ago when inappropriate and trivial sexual misbehaviour was more likely to be tolerated or overlooked, but your offending is not trivial but of a very serious nature and any perception to the contrary on your part is misconceived."

He said the offences did not come to light sooner because of Clifford's dominant character and his position in the entertainment world, which meant his victims "thought you were untouchable, something I judge that you, too, believed and traded upon".

The compassion shown by Clifford to his disabled daughter, Louise, who was not in court on Friday, was not shown to the girl he molested on holiday in Spain, the judge said. He added: "Although your charitable work has gone on long after your offending ceased, I cannot ignore that for decades you were leading a double existence."

Clifford will go on the sex offenders' register for life, meaning that when he is released he will only be able to live at an approved address and will have to notify authorities of his movements, including travel abroad.

But as Clifford was driven by prison van to Wandsworth prison, south-west London, his solicitor, Paul Morris, said they were considering an appeal against his conviction and "seriously considering" an appeal against the eight-year sentence.

Outside court, DCI Michael Orchard, the senior investigating officer in the case, thanked Clifford's victims for their bravery in contacting police.

He added: "My officers carried out a painstaking investigation to identify all historic and current evidential opportunities, to ensure this case was brought to trial. I hope this gives other victims the courage to come forward, knowing we will make every effort to investigate their allegations regardless of the passage of time.

"As a result of high-profile cases such as these we have seen a significant increase in the number of sexual abuse allegations reported to police.

"Our specially trained officers will continue to work tirelessly with colleagues at the Crown Prosecution Service to bring sex offenders, whether recent or not, to justice. Over the last 12 months we have seen an increase of 1,436 allegations of sexual abuse reported to the Metropolitan police."