Costs to date for the restoration of the historic Leinster Lawn have come to just €21,000, including €5,000 for the labour involved in ripping up the tarmac, the cost of top soil and "€50 worth of grass seed", an OPW spokesman said last week.

While this is less than one-tenth of the original estimated cost of €230,000 to restore the front of Leinster House to its previous glory, the OPW spokesman said the cost of putting in ducts, additional lighting and as well as security lighting will increase the final bill.

But it is not expected to go anywhere near the original estimate.

The lawn was ripped up almost 10 years ago to provide a car park for politicians, whose free spaces had been displaced by an extension to Leinster House in 2000.

While politicians were extremely reluctant to give up their free city centre parking facilities, they eventually had to bow to pressure from Dublin City Council planners who pointed out that a condition of planning permission for the 2000 extension was that Leinster House lawn be restored once the extension was finished.

But the chairman of the Oireachtas Commission, Ceann Comhairle John O'Donoghue, insisted that the OPW source alternate car parking spaces for politicians.