TAXI fares by Department of Foreign Affairs employees working abroad have run to €144,000 already this year.
The figure does not include fares claimed by officers travelling on official business who "may also find it necessary to use taxis and may be reimbursed for these costs".
Tanaiste and Foreign Affairs Minister Eamon Gilmore says the costs are monitored on a monthly basis and the taxi policy is kept under review.
He points out that this year's figure compares to a total cost in 2008 of €455,000 which was cut to just under €306,000 the following year and to €263,000 last year.
Mr Gilmore says current taxi policy only allows taxis for official business in cases where public transport is not feasible or not available.
Taxis are also provided when officers have to travel early in the morning or late at night.
"At other times the use of taxis is not allowed. I believe that this provides a reasonable balance between requirements to safeguard the exchequer and recognition that there are situations where the use of taxis will be necessary," he said.
In response to a question from Deputy Shane Ross, Mr Gilmore said the official taxi service was intended for staff of his department only and not made available to others.