Boeing's 737 Max

The discovery of a potential electrical problem last month led to the renewed grounding of more than 100 aeroplanes, belonging to 24 airlines around the world.

Deliveries of many more new aircraft have been suspended. Boeing and the US regulator, the Federal Aviation Administration say they are working closely to address the issue.

But the affair has given new energy to critics who claim the 737 Max was allowed back into service prematurely - and that issues which could have contributed to two fatal crashes have not been fully analysed or addressed.

It lifts a 22-month flight ban for the jet, which followed two crashes which caused 346 deaths.

The plane has already been cleared to resume flights in the US and Brazil.

This week a senior manager at Boeing's 737 plant in Seattle warned that recertification had happened too quickly.

But regulators in the US and Europe insist their reviews have been thorough, and that the 737 Max aircraft is now safe.

Easa executive director Patrick Ky said: "We have every confidence that the aircraft is safe, which is the precondition for giving our approval.