FINE Gael has called on transport minister Noel Dempsey to come clean about what he was doing at a secret meeting in London after he ran up a €23,000 bill for using the government jet.

The party has now asked information commissioner Emily O'Reilly to investigate the Department of Transport's refusal to identify whom Dempsey met.

The trip has already caused controversy for the minister after it emerged he had used the €7,890-an-hour Gulfstream IV to fly first to Derry and then onward to London.

Attempts by both Fine Gael and the Sunday Tribune to find out what he was doing in England have been resisted by the Department of Transport in "the public interest".

Fine Gael has appealed the decision to Emily O'Reilly's office asking her to intervene and find out exactly whom Dempsey was meeting.

"Minister Dempsey incurred a considerable cost to the taxpayer in his use of the government jet to attend this meeting," the party's appeal says. "[We] believe that it is absolutely in the public interest for the identity of the party met in London to be revealed. It is not acceptable that a large sum of taxpayer's money was used to hold a secret meeting in London with the details of that meeting, including those attending, withheld from the same paying public."

Fine Gael TD Leo Varadkar called on the department to explain what the meeting was about and put an end to controversy about the €23,000 flight.

The Department of Transport has refused access to the information on various grounds, effectively saying it relates to an ongoing consultation and a government decision.

Questioned about it, Dempsey simply said it related to jobs creation, but there has been no announcement from his department since the trip.

A redacted itinerary of the trip records that the minister was collected from his hotel on 20 July and taken to the Irish embassy. At 8am, he had a 90-minute breakfast discussion, described as "critical" by his own civil servants.

Access to the records was refused on the basis that revealing whom the minister met could upset delicate government negotiations.

In Fine Gael's appeal letter, it said that simply naming the party involved would not disclose the state's position on any matter.

"[We] reiterate the point that the public should have access to the identity of the party that the minister met with in London as the meeting incurred a considerable cost," said Fine Gael.