Master Leslie, a High Court official, ruled disclosure of a report into councillor and former Lib Dem MP Mike Hancock was necessary so that the woman could feel she had "a fair hearing and a fair crack of the whip".
The report was written by Nigel Pascoe QC, who was asked by the city council to investigate the allegations for code of conduct proceedings.
The woman, a female constituent and a young mother, says Mr Hancock made "unwelcome sexual approaches". The leaked, redacted version of the report describes the account she gave as "credible".
The alleged sexual assault victim of MP Mike Hancock has won a bid to force a Lib Dem-led council to make available a full version of a QC's report about her accusations at a forthcoming civil court action.
Portsmouth City Council, where Hancock is a councillor, opposed the application for full disclosure of the report - a redacted version of which has already been leaked to the public.
But Master Leslie, a High Court official, ruled disclosure was necessary so that the woman could feel she had "a fair hearing and a fair crack of the whip".
Lib Dem leader Nick Clegg said he "acted immediately" when he was told legal proceedings were being taken against MP Mike Hancock, who has been accused of sexual misconduct.
The Deputy Prime Minister said: "You can only react to things that are put to you and the first time that specific allegations were put to me was when legal proceedings were launched at the beginning of last year.
"That is when I acted, I acted immediately because I was as appalled as anyone by the seriousness of these allegations, and that's why I now want to see justice done.
"The process, which is now in the courts, should be seen through to its conclusion".
In an exclusive interview with ITV News Meridian under fire Portsmouth MP Mike Hancock refused to answer questions about his future. He was speaking to reporter Richard Jones.
Children could be offered free bus travel under plans being considered by the Liberal Democrats, according to the Daily Telegraph.
Deputy Prime Minister Nick Clegg was reported to be "very keen" on the proposal, which it is hoped would encourage older children to become more independent.
The report claims free child bus passes could be announced later this year as part of a package of measures that would include the Conservatives' tax break for married couples - a policy which has been ridiculed by the Lib Dem leader.
A senior Lib Dem source said it was too early to say whether the free bus travel plan could be delivered, adding that it was "jumping the gun" to suggest it formed part of the party's negotiating strategy with their Coalition partners.
The Met Police said a 59-year-old man was arrested on Tuesday in Kingston, on suspicion of possessing indecent images of children.
He was taken into custody at a south London police station and bailed to a date in August.
According to the London Councils' website, Liberal Democrat Kingston-Upon-Thames council leader, Councillor Derek Osbourne, was first elected as a councillor in 1986 before becoming leader between 1997 and 1998, and again in 2003.
He was parliamentary candidate for Kingston upon Thames in 1992 fighting the then Chancellor Norman Lamont.
A Liberal Democrat council leader has resigned after being arrested on suspicion of possessing indecent images of children.
Councillor Derek Osbourne, who has been leader of Kingston upon Thames since 2003, was arrested by police on Tuesday.
Derek Osbourne has resigned from the Liberal Democrat Group.
We are deeply shocked by these allegations but I am unable to comment further as we must now allow the police the time and space they need to investigate the allegations thoroughly and without prejudice.
The new acting leader of Kingston Council said the local Liberal Democrat group were "deeply shocked" by the arrest.
Nick Clegg has blocked Conservative-backed plans to allow nursery staff and childminders to look after more children.
The Deputy Prime Minister said that after consultations with parents, he did not believe the proposal would raise standards or bring the price of childcare down.
Leader of the Commons Andrew Lansley was forced to defend the Government's stance on childcare after Nick Clegg blocked Conservative plans to review the ratio of nursery staff to children.
Labour MP Andy Sawford told Mr Lansley it was "shocking" there had not been a statement to the House of Commons on the issue.
"If you will not arrange a statement, can you at least tell us what the current policy is? The Deputy Prime Minister said yesterday it's been dropped - you told us this morning it's being reviewed", he continued. "What is the policy? It's a shambles".
Mr Lansley replied: "Our policy is to ensure the quality of childcare increases and the affordability for parents is improved.
"That is what we are setting out to do, it's what we will do. As soon as policies have been agreed, there will be an opportunity for that to be brought to the House for announcement".