Fianna Fáil environment spokesperson Timmy Dooley is seeking to have the ESB brought before an Oireachtas committee to answer questions about safety and environmental concerns.

It follows last night's RTÉ Investigates programme The ESB Leaks which revealed up to one million litres of oil has leaked from underground cables over a 20 year period.

Watch the programme here.

Minister for Communications, Climate Action and Environment Richard Bruton has also expressed concern about the revelations.

Mr Bruton's department confirmed today that it has received a protected disclosure about the oil leaks from a whistleblower and ESB employee, Séamus O'Loughlin.

The protected disclosure revealed underground ESB cables have been leaking insulating oil at sites close to the Grand and Royal Canals in Dublin city over two decades and the ESB failed to inform any of the relevant authorities about almost any of the leaks.

Today the Green Party called on ESB Networks to release all information about the oil leaks which happened at various locations and which the ESB described in its own internal documents as environmentally sensitive.

The party's newly elected Dublin MEP Ciarán Cuffe also called on the ESB to put in place plans to clean up the sites polluted by the oil leaks.

"It is deeply worrying that a State company could allow mineral oils to pollute land and waters in the heart of Dublin for decades without informing the public, or apparently the Environmental Protection Agency," Mr Cuffe told RTÉ.

"Both Minister Richard Bruton and the Environmental Protection Agency must now put in place investigations that examine the system failure that led to these events," he said.

Social Democrats co-Leader Catherine Murphy has described as "horrifying" the revelations in last night's programme.

She said the environmental damage caused by underground leaks has been largely ignored by the ESB over a number of years.

"The revelations that significant amounts of oil are still being leaked from ESB pipe-lines shows at best a flippant regard for environmental concerns by the ESB and at worst a complete disregard for the environment," she said.

In a statement, Louth Fine Gael TD Fergus O'Dowd condemned the ESB for its treatment of Mr O'Loughlin. 

 "Their treatment of the ESB whistleblower Séamus O'Loughlin has been disgraceful and unacceptable; I believe he should be restored to his former position within the organisation.

"It's time to tackle the unfettered power of the ESB," said Mr O'Dowd, "and make it more accountable to the public and the Oireachtas. Ministers in the past have tiptoed around this company with bated breath and refused to challenge their monopoly."

The ESB has said at all times it treated Mr O'Loughlin fairly and listened to his concerns.

The company said it takes its environmental and reporting obligations seriously.

It has also said that the cables contain a fluid called linear alkylbenzene which it says is biodegradable.

However, 90% of the cables also contain a mineral oil from the 1970s which is not readily biodegradable.

The ESB said it will engage with an investigation by the Environmental Protection Agency.

The EPA launched the investigation after it received details about the leaks from RTÉ Investigates.