NICOLA Sturgeon has signalled an end to her controversial plan to give a £150m tax break to the airline industry in light of growing concerns over climate change.

The First Minister said she would “reconsider” the SNP’s manifesto promise to halve and then abolish air passenger duties in Scotland.

Her official spokesman said it was “clearly part of the mix” in a new evaluation of how Government policies affected the environment.

He said: “The climate change agenda presents you with difficult choices and difficult challenges. This falls into that category.”

Read more: Act now or all hope for planet will disappear, climate change report warns

The tax cut, devised by Alex Salmond, was intended to boost Scotland’s economy but has been widely criticised as it would also add to carbon emissions by increasing flights.

At the 2016 Holyrood election, the SNP promised a 50 per cent cut in Air Departure Tax - the proposed devolved version of Air Passenger Duty - by 2021.

However the policy has stalled, leading to anger from an airline industry that expected it.

It is also vehemently opposed by the Scottish Green MSPs on whom the minority SNP administration has relied to pass its last three budgets.

It has already been delayed three times because of financial problems and looks increasingly undeliverable within the current parliament.

Last month ministers said it would not be ready for the start of the 2020/21 tax year, the last full tax year, of the parliament because of a wrangle over EU state aid rules.

Ms Sturgeon last week declared a “climate emergency” to help avoid runaway climate change and yesterday said her government would toughen up targets in light of a new report from international experts.

Responding to the latest Climate Change Committee report, she said the targets in the Climate Change Bill now going through Holyrood would be hardened, with Scotland to be carbon neutral by 2040 instead of 2045, provided the UK did the same for 2050.

But Committee chief executive Chris Stark said abandoning the ADT cut would “help immensely with the emissions challenge there is in Scotland”.

Read more: First Minister's Questions as they happened

At First Minister’s Questions, Scottish Labour leader Richard Leonard said the £150m air tax cut would benefit the richest people the most and drive up emissions.

He said SNP plans to factor the extra emissions into climate targets was “simply not good enough” and the FM should drop it if she was serious about a climate emergency.

Ms Sturgeon replied: “The reduction in air departure tax is not going ahead this year.

“The increase in our scale of ambition today will mean that we need to reconsider policies across the whole range of our responsibilities.”

“We are committed to published a revised climate changes within six months of the new legislation being passed. So we will need to, right across a range of responsibilities, look at where we’re going to increase the scale of our ambition.

“We do not shy away from our responsibilities here.”

She added that if Labour wanted to be taken seriously on climate change, Mr Leonard would need to “rethink” his position on green policies such as a workplace parking levy.

After FMQs, the FM’s official spokesman confirmed the ADT cut was being re-evaluated.

He said: “The underlying message from the FM was that all policies will now need to be look at with a view to the enhanced targets that are being set, that we are adopting, as a result of the Climate Change Committee recommendations.

“Air Departure tax is clearly part of the mix. We are not in a position where we’re about to enact any imminent policy change on that anyway for well-known reasons.

“And further it, along with a whole range of relevant policies, will be part of this evaluation.”

Asked if the Government might drop the ADT plan altogether, he did not deny it.

He said: “It’s very clear that that policy now, along with a whole raft of policies that impact on emissions and climate change targets, will be evaluated and re-evaluated in terms of where we need to get to.”

Asked about the ADT cut being a manifesto commitment, he said: “These things are not easy. The climate change agenda presents you with difficult choices and difficult challenges.

“This falls into that category.

“It’s also incumbent on other parties not to resort to other parties not to resort to knee-jerk opposition to things like workplace parking [levies] if they’re serious.”

The SNP plan to take over and cut ADT has been stymied by an exemption from air passenger duty given to Highlands airports in 2001 to help them boost their traffic.

If the tax was devolved, to become ADT, there are fears this historic opt-out would fall foul of new EU state aid rules, and costs would soar.

The standard tax rate is currently £26 for short haul and £172 for long haul flights.

Ms Sturgeon was also urged to drop the ADT cut by the LibDems and Greens at FMQs.

Green parliamentary co-leader Alison Johnstone said: “Now that the Scottish Government has declared a climate emergency, it is time to scrap the unfair and environmentally damaging proposal to cut taxes for wealthy frequent flyers and instead invest in everyday transport like buses, trains, walking and cycling.”

LibDem MSP Liam McArthur said: “The First Minister should accept this [Climate change Committee] advice, scrap the aviation tax and use the money instead to deliver on an early target for government and public bodies to phase out their polluting vehicles.”

A spokesman for Edinburgh Airport said: “The Scottish Government already implements a successful cut in APD in Inverness which has delivered fantastic economic benefits.

“We firmly believe that an APD cut should be used a lever to so the same for Scotland as a whole, boosting our economy during these turbulent times.

“Climate change is an issue we must all face into and we believe this can be done whilst maintain strong economy and connectivity.

“This allows our country to invest in carbon reduction without closing itself to the world.”

Industry body Airlines UK said: “Airlines continue to believe that lower levels of taxation on aviation will provide a much needed boost to connectivity and make Scotland a more attractive place for carriers to add capacity, delivering new routes and more services.”