The Department of Agriculture on Kildare Street, Dublin

An underground tunnel between Leinster House and another building on Dublin's Kildare Street is being proposed to shorten the 100-yard journey for busy TDs and senators.

Construction of the tunnel from the seat of parliament to Agriculture House – both of which are on the same side of Kildare Street – could begin this summer if it gets the go-ahead from a committee of TDs and senators who are currently considering the project.

Neither the Office of Public Works nor the Oireachtas could put a price on the project last week nor could they explain why it might be necessary to build a tunnel when the distance between the two buildings is less than 100 yards across closed-off roads.

The OPW said the tunnel would incorporate a direct access link between the two buildings "at below-ground level".

"Creating this link will involve minor structural adjustments to existing rooms and corridors at basement level in the two buildings and will not involve any major construction work," a spokesman said.

The project is part of the overall restoration works on Leinster House, which will restart when the Dáil rises for the summer holidays in early July and go on until late 2011.

Under a long-term plan for Kildare Street and the surrounding area, Agriculture House will become a permanent overspill for Leinster House. The building already houses the Emergency Planning control centre and there are plans to put a new media centre in the building also.

Fianna Fáil TD Michael Mulcahy, former Labour leader Pat Rabbitte and Fine Gael senator Paul Bradford have been selected to examine the feasibility, with the OPW, of the tunnelling ­project.