The Conservative party has pledged to reform Air Passenger Duty if it wins the May 6 election, but will not scrap the tax.

The pledge in the Tory manifesto will be welcome in the industry. An Abta petition calling on the government to reconsider the near doubling of APD due this November has attracted more than 14,000 signatures.

However, the overall tax on flying is unlikely to change under the Conservatives, who intend “to encourage a switch to fuller and cleaner planes” by relating the tax to emissions. They have not said how they would do this.

At the same time, the manifesto affirms a Tory government would halt airport expansion. It promises: “We will stop the third runway [at Heathrow]. . . [and] block plans for second runways at Stansted and Gatwick.”

The Liberal Democrat manifesto also pledges to cancel “any expansion at airports in the South East” and to replace APD with “a per-plane duty (PPD)” that would include cargo flights.

However, the Lib Dems would expect the new tax to raise an extra £3 billion a year. They would also seek an additional £255 million a year through increased duty on domestic flights.

Labour’s manifesto makes no mention of APD, although the party is committed to raising the duty this year. However, its manifesto affirms support for expanding Heathrow.

There are few other references to travel, apart from rail, in the manifestos.