Lord Archer's former secretary yesterday told the Old Bailey she had helped his "deception" over diaries because she did not want to lose her job.
Mrs Angela Peppiatt denied receiving any "financial incentive" to put entries into a blank diary before the millionaire author's libel case against a newspaper which had claimed he had had sex with a prostitute.
Mrs Peppiatt (56) claims she accepted Lord Archer's explanation that the original diary's political sensitivity had to be protected when he presented her with the blank diary and a list of entries for a day in September 1986.
But she decided to make photocopies when she was asked to take the diary to Lord Archer's solicitors. "When it got to this stage it was a much deeper deception, if you like," she said.
Mr Nicholas Purnell QC, defending Lord Archer, asked her: "There was no financial incentive for you to do this?"
She replied: "I did not wish to lose my job."
Mr Purnell: "There was no extra incentive over and above your wages, no reward thereafter?"
Mrs Peppiatt: "No."
Lord Archer (61) denies seven charges including perverting justice and perjury in relation to a libel action against the Daily Star which resulted in him being awarded £500,000 damages. His former friend, a television producer, Mr Ted Francis (67), denies perverting the course of justice in relation to an alibi which was not used in court.
The prosecution alleges that Lord Archer produced a forged version of Mrs Peppiatt's office diary and tampered with his own to cover his movements before the High Court hearing.
Mrs Peppiatt, who now works for an educational charity, was Lord Archer's secretary for three years, during which time he was appointed deputy chairman of the Conservative Party.
She said Lord Archer kept a picnic basket full of signed cheque books in his riverside apartment in central London.
She could not remember how many accounts he had but she thought there were six, including ones for business, private use, shares and theatre.
He would sign several cheques in his various cheque books for her to fill out including those for staff wages, said Mrs Peppiatt.
"I would tell him when we were running out," she said.
"We had a sort of picnic basket which was kept on the shelf of Alembic House (Lord Archer's riverside apartment), in which the cheque books were kept."
One of her functions was to keep his diary and prepare a daily card for him listing his immediate engagements.
She said: "Jeffrey didn't carry more paper than he needed to."
She agreed that Lord Archer was paying her about £22,000 a year, substantially more than other staff at Conservative Central Office were receiving.
Questioned by Mr Purnell about her claims about the blank diary, Mrs Peppiatt replied: "I have told you the truth."
The trial was adjourned until today.