The case is being brought by Michelle Williamson, whose parents were among nine people killed in an IRA bomb attack on the Shankill Road in Belfast six years ago.

The judicial review will take place in two weeks time.

After the hearing, Mrs Williamson said: "I am delighted that finally I might be given the chance of justice for my mother and father and all the innocent victims."

BBC News' David Eades reports on the legal challenge to the ceasefire

Ulster Unionist leader David Trimble, who accompanied her into court, said: "This is merely the first step of what will be a fairly lengthy and complex process.

"I see it as a matter of upholding the (Good Friday) Agreement."

He said the UUP had not brought the action itself because the law required it to be put forward by an individual with sufficient personal interest.

Granting leave for the action, Mr Justice Kerr said Monday's decision was in no way prejudicial to the final outcome of the case.

He said: "It's clear to me that the applicant has an arguable case. The applicant at this stage need only satisfy the modest test of showing she has a case which requires further inquiry."

In a brief comment, the government said it would respond vigorously to any challenge.

A Northern Ireland Office spokesman said it believed Dr Mowlam had acted properly according to the law, in making her determination.