Airlines have criticised Conservative plans for new environmental taxes on flights to combat climate change.
The Tories say air taxes would be offset elsewhere
Virgin said the taxes would damage the UK economy, and British Airways called them an "extremely blunt instrument" to tackle carbon emissions.
The proposals include levying VAT or fuel duty on domestic flights and a green air miles scheme.
Shadow chancellor George Osborne said the taxes would be targeted at frequent fliers and not family holidays.
Another measure under consideration in the Greener Skies consultation paper is scrapping air passenger duty and replacing it with a new "per flight" tax based on carbon emissions.
The party publishes the document on Sunday and will ask people for their views on various proposals.
Mr Osborne said: "We're saying that taxes on aviation need to increase.
"That's because we think you need to take the tough long-term decisions to tackle climate change."
But he said the taxes needed to be designed so that they did not "hit people who only have one package holiday a year" and that they target "more dirty engines on aeroplanes".
"That way we have the maximum environmental effect and we also don't tax people out of their one foreign holiday a year," he said.
He added that the measures would not mean an overall increase in taxes for families because for every pound the party increased aviation taxation, a pound would be cut in taxes elsewhere.
Virgin Atlantic said "green" taxes would not work and urged the Conservatives to invest instead in developing lighter and cleaner planes and fossil-free fuels.
The airline's communications director Paul Charles said the proposals "would damage the UK economy" because they would "make UK airlines less competitive and shift jobs to other countries in Europe".
British Airways said taxation was "an extremely blunt instrument in terms of reducing carbon emissions".
Easyjet dismissed air passenger duty as "probably the worst tax ever invented" but it gave a cautious welcome to the idea of a "per flight" tax, saying it would help to sideline airlines using "dirty" aircraft.
Chris Goater from the Airport Operators Association said aviation accounted for a very low percentage of world CO2 emissions, and that the issue had to be tackled internationally.
Transport Secretary Douglas Alexander accused the Tories of being "more interested in making a headline".
He said: "There is no evidence they have thought through these proposals.
"At the most basic level the taxation of aviation fuel is governed by international law and cannot be changed at a whim."
The Treasury said the green taxes would not have the intended effect of reducing greenhouse gases.
Dave Timms of Friends of the Earth welcomed the proposals to tackle the environmental problems of air travel.
He said: "Aviation is the fastest growing area of the UK's carbon emissions, and if we don't do something about it we have no chance of meeting international targets, or any targets that the government might set."
BBC News political correspondent Robin Brant says Conservative leader David Cameron feels the environment is a vote winner.
Our correspondent said: "The Conservatives are saying this is about shifting the burden of taxes, so some people will pay more in tax, but there are others they claim - families - who will pay less tax. That's the way they are presenting this."