Pilots reported at least seven near misses with objects which may have been balloons in UK airspace last year.

Analysis of UK Airprox Board (UKAB) data by the PA news agency revealed the extent of the close encounters one day after Rishi Sunak said the Government will do “whatever it takes” to keep the UK safe from the threat of spy balloons.

The Prime Minister made the comment following the decision by the US authorities to shoot down a series of objects in western airspace in recent days, including a suspected Chinese spy balloon.

The analysis of UKAB reports found that on December 17, the pilot of an EV97 light aircraft flying at 1,850 feet above Enfield, north London reported an object that “could have been a balloon or an egg-shaped drone” flying “directly below them by 50-200ft”.

An air traffic controller told the board on September 25 a pilot in the cockpit of an Airbus A319 airliner was “distracted” by an object which was “either a balloon or a drone” passing along the side of the plane.

The pilot said it was in “close proximity” and described it as a “white object, considered to be a threat” and “rectangular”.

Four days later, a pilot on a Boeing 737 taking off from Stansted Airport, Essex reported seeing “a glinting object” as near as 50 metres away.

The pilot “first thought it was a balloon”, but then believed that was unlikely given it was at an altitude of 9,000 feet, so believed it was a drone.

On July 2 a pilot of a Boeing 757 plane saw “what was first thought to be balloons” at 7,500 feet shortly after departing from Manchester Airport.

The report went on to state that “as the black object passed down the right-hand side it looked like a drone”.

On July 16, the captain and first office in the cockpit of an Airbus A320 near Hatfield, Hertfordshire noticed an object which was “grey/silver in colour and about the size of a large drone or balloon”.

It was “almost shiny in appearance” and passed “within 100-200ft below their aircraft”.

The UKAB concluded that the incident had the second-highest level of risk as “safety had been much reduced below the norm”.

On June 3, the pilot of an Airbus A321 aircraft at 34,000 feet above Norwich saw “a small white weather balloon”.

The first officer onboard an ATR 72 turboprop plane approaching Liverpool John Lennon Airport on April 8 observed “a small silver coloured object” about 10 metres away from the right wing at 3,500 feet.

The report added: “As the object was only visible for three seconds it was not enough time to determine whether it was a balloon or a drone.”

The UKAB concluded that the incident had the highest level of risk as “a definite risk of collision had existed”.

In October 2017, the Met Office said it “launches over 4,300 balloons every year from six locations across the UK” and is “involved in launching thousands more around the globe”.