Plans to expand Stansted Airport have been refused by a local council, despite approval last year.
Uttlesford District Council said the airport's plans to increase its passenger numbers must be reviewed again by its planning committee.
Brian Ross from campaign group Stop Stansted Expansion said it was "the right thing to do".
Stansted said it was "concerned" by the decision and there was "no legitimate reason" for the refusal.
The airport handled 28 million passengers in 2018, with the capacity for 35 million per year.
It wants to expand to 43 million passengers, which would take it three million behind Gatwick.
This could be done by making better use of the airport's single runway, without breaking caps on flight numbers or aircraft noise, it said.
It is also planning to build a new arrivals terminal and more car parks as part of a £600m investment in its facilities.
Last year, Uttlesford District Council provisionally approved the plans but following a change in ruling party and a 1,600-strong petition an extraordinary meeting was called.
In the local elections in May, the independent group Residents for Uttlesford took control of the council from the Conservatives.
Council leader John Lodge said the government's plan to cut greenhouse gas emissions to almost zero by 2050 influenced the decision.
He said that had not be considered when plans were submitted and they now needed to look at "the bigger picture".
"The council has a responsibility to make sure it gets that consideration", he added.
Stansted said it was "frustrated" and local businesses and residents had backed its plans.
It added that the increase in passenger numbers would not see flights or noise pollution increase.
- 14 November 2018