Alex Salmond, Scotland’s former first minister, has been accused of being a “sexual predator” who abused his power to sexually assault women for personal gratification.

A jury in Edinburgh was told by the prosecutor Alex Prentice QC on Thursday that Salmond preyed for nearly eight years on young, aspirational women who worked for him while he was first minister, often when they were alone at night.

“This case isn’t about a plot or political conspiracy,” he told them. “This is about a powerful man who abused his power to satisfy his sexual desires with impunity.”

Summing up after nearly nine days of evidence, Prentice invited the jury of nine women and six men to convict Salmond of one charge of attempted rape, an intent to rape, nine charges of sexual assault and two of indecent assault – charges that Salmond denies.

Prentice told the jurors: “Ladies and gentlemen, they had no one to turn to for an effective remedy. Well, they do now.”

Prentice said the testimony from the nine complainers, the Scottish legal term for complainants, painted a compelling picture. There was an “emerging pattern of brazen conduct; he did it because he could”.

In several cases, women were assaulted in public, including in a ministerial car, at Stirling castle and at a nightclub, Prentice told the jury. In one incident not among the charges, he said a senior civil servant witnessed Salmond’s attempt to stroke a female official’s hair and slapped his hand way.

He is also accused of assaulting women in Bute House, the first minister’s official residence in Edinburgh’s new town, where one complainer accused him of an attempted rape in June 2014 and another of intent to rape in December 2013. Both women allege that they had been plied with drink. Eight of the charges involved alleged attacks at Bute House.

“Alex Salmond’s conduct over the span of these charges was intimidating, humiliating and degrading, and created an offensive environment,” Prentice told the jury. “The complainers in this case are courageous, brave women who spoke up to call out the abusive conduct of the former first minister.”

They were “entirely credible and entirely believable” witnesses, he said, who had no reason to lie about such serious allegations. “The common theme, I suggest, is of a comprehensive, compelling and convincing course of conduct.”

Salmond, who denies all the allegations, was formally acquitted of a 10th charge of sexual assault on Monday after the prosecution withdrew the charge. His defence lawyer, Gordon Jackson QC, is due to address the jury on Friday.

Prentice said Salmond was clearly an extremely effective politician, who could be a great, if demanding, boss. But he said the jurors had to focus on the testimony and the evidence. They had to decide whether a crime was committed and, if so, was Salmond responsible.

Salmond had been described by some witnesses as a tactile person, Prentice added, “but that is not a licence to grope women”.

Salmond’s former policy chief, Alex Bell, told the court earlier on Thursday he had been in Bute House, the first minister’s official residence, the night that a senior civil servant was allegedly forced by Salmond to reenact a painting showing an older man kissing a young woman in late 2010.

The official has accused Salmond of grasping her wrists and pulling her towards him, and ignoring her attempts to remove his hands. “He was very persistent and I felt like I was wrestling with an octopus,” she told the court on Monday.

Bell said “B” was on her own with Salmond in the drawing room as the then first minister’s team prepared for first minister’s questions, known as FMQs, the next day. Bell, who was then Salmond’s head of policy, said two other members of Salmond’s staff asked him to go up because B was alone with Salmond.

“I do recall as we were midway through FMQs prep, after the meal, that I went down to the office, and Graeme Roy and Sarah Govan said to me: ‘You’ve left [B] alone in the office. Would you go up?’” he told Salmond’s defence lawyer, Shelagh McCall QC.

Bell could not recall where B and Salmond were standing, but said he had coughed or cleared his throat before entering the room. He did not remember B seeming upset. Alex Prentice QC, the lead prosecutor, asked Bell why he went back upstairs. “To ensure that the welfare of my colleague was OK,” Bell said.

Roger Cherry, who served as Salmond’s government driver as first minister from 2007 to 2014, told the jury he did not see Salmond allegedly holding the leg of an SNP politician while they sat in the back of a government car in February 2011.

The SNP politician, known as C, said she was “gobsmacked” and “totally taken aback” when he put his hand on her leg and left it there for the duration of a short drive through Edinburgh. Cherry said he had no memory of that happening; Salmond denies ever doing so.