More than a year after her appointment was declared an illegal political favour to the DUP, appeal judges were told that Mrs McDougall was not aware that she was the only person interviewed for the job.

In an affidavit, Mrs McDougall - whose name was put forward by the DUP and approved by the then Secretary of State Peter Hain - said she "assumed other candidates for the job were being approached in a similar way".

The High Court ruled last year that Mrs McDougall had been illegally appointed by Mr Hain and sparked an investigation into whether the Northern Ireland Office tried to cover up the facts of the appointment.

The Attorney General's probe found there was no deliberate attempt to mislead the High Court, but criticised the head of the Civil Service, Nigel Hamilton, for an " unacceptable" evasion of truth about Ian Paisley's role in nominating Mrs McDougall.

The NIO's appeal against the decision opened in Belfast yesterday, and the Court heard that Mrs McDougall said she was initially approached about the job by DUP MP Jeffrey Donaldson.

After speaking to him twice and meeting Dr Paisley - who then recommended her in a handwritten letter to Mr Hain - she was interviewed by Mr Hamilton and the NIO's Permanent Secretary, Jonathan Phillips.

Nineteen days after the initial approach by Mr Donaldson, she was told the £65,000-a-year job was hers.

Bernard McCloskey QC, appearing for the NIO, told the appeal judges that Mrs McDougall was aware that the job was not advertised, but assumed there was "head-hunting type process" underway.

He said the NIO had an initial list of 16 names to appoint to the post, but narrowed it down to two.

Mr McCloskey said the "thrust and spirit" of guidelines for public appointments had been observed by the NIO.

He argued that Mrs McDougall has no "association with any political party".

The Lord Chief Justice, Sir Brian Kerr, said: "I suppose that depends on how one defines 'association'."

But the QC insisted: "Mrs McDougall has no alignment or association of any kind with the DUP."

Mr McCloskey said that during her year in the post, Mrs McDougall had shown she could do the job, which "amply demonstrated she was properly appointed".

"Her appointment was an appointment on merit," he said.

"The assessment that Mrs McDougall was capable of commanding cross-community support was unerringly correct."

The case continues.