Spare parts for those drones as well as helicopters and ground-level targeting equipment are all covered by the partial embargo announced by David Lammy, the Foreign Secretary, on Monday.

Israeli intelligence is also vital for combating Islamist terrorist threats in the UK and Europe – threats that remain “substantial” on current reckoning (the midpoint on the UK’s five-point scale run by Joint Terrorism Analysis Centre and MI5).

Israeli intelligence was reported to have contributed to a series of anti-terror arrests made in Germany and Denmark in December, for example.

‘You only embolden Hamas’

It may also have played a part in foiling the IS-inspired plot to attack a Taylor Swift concert in Vienna in August.

“They planned to kill a huge number of people, tens of thousands at this concert,” said David Cohen, the CIA deputy director, last week. 

“The Austrians were able to make those arrests because the agency and our partners in the intelligence community provided them information about what this IS-connected group was planning to do.”

No one is suggesting Israel would now deliberately withhold such information but intelligence is by its nature a co-operative and transactional business that works most efficiently when trust is high and relations are good.