A climate change minister has stood by his criticism of airlines' efforts to tackle carbon emissions.
Ian Pearson said aviation was a growing industry which would have "growing CO2 emissions" and must take more action.
Mr Pearson also described Ryanair as the "irresponsible face of capitalism". But its boss, Michael O'Leary, said "he did not know what he is talking about".
Mr Pearson told BBC News he did not want to get into a "war of words" but "everybody has got to do their bit."
Earlier he said the attitude of US airlines to emissions was a "disgrace".
Mr Pearson added: "Everybody has got to do their bit.
"Every industry has got to do their bit and aviation can't be an exception and my role as climate change minister is to get aviation into the emission trading scheme as quickly as possible.
"I do not want to get into a war of words, but the key point here is that climate change is a here and now issue, it is really important - we need to do something about it.
"Aviation is a growing industry and it's going to have growing CO2 emissions.
"We need to get aviation into the EU emissions trading scheme just as quickly as possible and that's got to be a priority for us a government."
In an interview with the Guardian, Mr Pearson had said: "When it comes to climate change, Ryanair are not just the unacceptable face of capitalism, they are the irresponsible face of capitalism."
He also attacked British Airways, saying it was "only just playing ball" on environmental regulations, and Lufthansa, the German airline.
Mr O'Leary defended his company and the industry as a whole saying: ''We are the greenest airline in Europe."
"What he [the minister] should be attacking is the power generation stations and the road transport who between them account for over 50% of emissions," he added.
Even though his company was growing, the new planes it had invested £10bn in the last five years had cut its emissions and fuel consumption by 50%, Mr O'Leary said.
He added: "He hasn't a clue what he's talking about and is attacking the wrong target in the airlines."
Green Party MEP Caroline Lucas said Mr Pearson should resign or scrap the government's aviation expansion plans.
"If anyone other than a government minister had made them they would have been a useful contribution to our efforts to tackle climate change," she said.
"But for someone with collective responsibility for the government's support of the biggest expansion of the aviation industry in a generation to do so is nothing less than a deceptive admission of failure."
Chancellor Gordon Brown attempted to boost the government's green credentials in his pre-Budget report by doubling air passenger duty from £5 to £10 on short haul flights. Passengers on long haul flights could pay up to £80 extra.
But green campaigners said the increased levy would make little difference to emissions.
Friends of the Earth said if the government was serious about fighting climate change it should scrap airport expansion plans and tax breaks for the air industry.
Ryanair has opposed efforts by the EU to control aviation carbon emissions by including them in a trading scheme, saying it would discriminate against low-cost airlines.
The EU's scheme will see airlines pay for exceeding their current level of emissions.
Flights within Europe will come under the jurisdiction of the Emissions Trading Scheme by 2011.
The scheme would be expanded from 2012 to include all international flights that arrive at or depart from an EU airport.
Airlines would be issued with pollution permits - those that cut emissions would be able to sell their surplus while an airline that increased its emissions would have to buy more permits. The US has already questioned whether it would be legal within global trading rules to force airlines flying into the EU to take part in the scheme.
And there are reports that US airlines are considering legal action to overturn the EU's efforts.
In a statement, the Department for Environment, Food and Rural Affairs said: "Urgent progress is needed to ensure that aviation addresses its climate change impacts."
Toby Nicol, spokesman for Budget airline Easyjet, said the company "stands full-square with the government" on the proposal to include EU internal flights and international flights in the carbon trading scheme.