Mr Jackson, 60, who is married with three adult children, said yesterday: "This is a ridiculous allegation, and my conscience is clear before God."
The decision to charge the dean was made after the Bishop of Lincoln and a specially chosen solicitor had examined the evidence. The bishop said yesterday in a statement: "Certain allegations have been made against the dean by a lady member of the Cathedral congregation. The lady alleges that - with her own full consent and indeed encouragement - the Dean engaged in an improper, albeit brief, sexual relationship with her in the latter part of 1993."
If found guilty, Mr Jackson can be defrocked. He could have been suspended until the trial, but the bishop has chosen not to do this. However, he will take leave of absence until the hearing, which is expected some time in the next three months.
The case will be heard in front of the Chancellor of the diocese, His Honour Judge Michael Goodman, assisted by two lay and two clerical assessors. Mr Jackson strenuously denies the claims, which were first made in February last year.
The dean has been charged under the Ecclesiastical Jurisdiction Measure of 1963, which has been generally criticised as cumbersome and expensive. The last contested trial of a clergyman for adultery ended up costing the Church more than £300,000 in 1992, when the Rev Tom Tyler, a Sussex clergyman, lost his second appeal against a conviction for conducting affairs with parishioners.
Ever since his arrival at Lincoln Cathedral in 1988, Mr Jackson has been locked in often noisy conflict with other chapter members. He was appointed by Margaret Thatcher with a brief to sort out the quarrelsome chapter, whose four other members took full advantage of a medieval constitution to thwart any dean's attempts to run the place. Mrs Thatcher is said to have told her appointments secretary that she did not know Mr Jackson personally but "I know of him - there'll be blood on the carpet of Lincoln Cathedral before he's finished''. He attempted to force the resignation of the sub-dean and treasurer, Canon Rex Davis, for taking the cathedral's copy of the Magna Carta on a loss-making expedition to Australia. The trip to Expo 88 in Brisbane left the cathedral with a net loss of £56,000.
In 1990, the bishop launched a formal inquiry into the running of the cathedral, the first of its kind this century. After spending £20,000 on this, he concluded that all the chapter members should resign. This they refused to do. Canon Davis told a journalist last autumn that merely being awkward was no reason for sacking anyone. Only immorality could provide that.