No one doubts that competition is hotting up in the electricity market, but the latest move by the ESB's competitor Viridian indicates that the Northern Ireland company is intent on bringing the battle, literally, to the front door of the State monopoly.

The Margin hears the Northerners have secured office space on Lower Fitzwilliam Street, directly across the road from the entrance to the ESB's headquarters.

Both companies will have a strong interest in the comings and goings into their respective offices.

But if the ESB moves from its valuable city centre property to another in Leopardstown, as is proposed, Viridian may very well claim victory on at least one element of the power war.