The announcement that around 800,000 Volkswagen vehicles are showing irregularities in their CO2 emissions is the latest setback to befall the troubled German car manufacturing giant.
The estimated cost of the discovery to VW is thought to total €2bn, although the company have said that "a reliable assessment of the scale of these irregularities is not yet possible."
MEPs have reacted angrily with the European Parliament's Green/EFA group environment spokesperson Bas Eickhout, telling the Parliament Magazine, "that the fact the cheating is now extending to CO2 and gasoline cars shows how far-reaching this scandal is."
"This also casts doubt on how rigorously Volkswagen is handling this issue. This shows again how crucial it is that the European Commission takes the initiative in making sure all mishandlings are investigated as soon as possible to provide maximum clarity to all EU citizens."
The irregularities were discovered made during the course of internal investigations and is separate to the ongoing scandal over software cheating emission tests which has affected 11 million vehicles globally so far.
Volkswagen have not yet released details of which vehicles are thought to be affected, though the statement said petrol run cars have shown signs of irregularities for the first time.
Seb Dance, Parliament's Socialist & Democrats group environment spokesman added, "With the Paris [COP 21] climate change summit getting underway in under a month, false reporting of CO2 levels in 800,000 cars across Europe is really troubling."
"Every day seems to bring a new revelation, a new controversy, and a new admission. It is all testament to just how flawed the current emissions testing regime is, and how deep the level impropriety at VW goes."
Julie Girling of the European Conservatives and Reformists grouping, commented, "This is a very worrying development. It seems remarkable that weeks' after the initial revelations, VW are apparently uncovering new information. Who can say how much more evidence of wrongdoing is still to come. I think the public are losing confidence in VW and the car industry in general."
In a press release, Matthias Muller, VW's chief executive, said, "From the very start I have pushed hard for the relentless and comprehensive clarification of events," continuing, "we will stop at nothing and nobody. This is a painful process, but it is our only alternative."
He added, "The Board of Volkswagen wishes to underscore its determination to systematically continue along the present path of clarification and transparency."
The announcement is the second scandal to rock the company this week, as US environmental regulators announced that it is now investigating the carmaker for using devices to cheat emissions tests in its luxury diesel vehicles, drawing Porsche and Audi into the scandal.
In response to the allegations, Porsche has stopped selling one of its most popular models - the Porsche Cayenne Diesel - until the matter has been resolved.
Volkswagen has denied the US Environmental Protection Agency's accusations, saying, "No software has been installed to alter emissions characteristics in a forbidden manner."
More than €4bn has been wiped off Volkswagen's market capitalisation today (4 November) as the CO2 scandal has broken, with shares plunging 10 per cent.
Since VW admitted to cheating emissions tests in September its market value has reduced by €24bn.