British pilots will join flight crews from other countries today in a warning that flying hours were putting passenger safety at risk.
Pilots from 36 countries will protest outside the European Parliament in Brussels, claiming there is scientific evidence to prove that the EU's pilot flight time rules were "flawed."
Jim McAuslan, general secretary of the British Airline Pilots Association (Balpa) has written to Transport Secretary Lord Adonis warning UK standards are threatened by EU laws.
Pilots across Europe protested three years ago that plans by the European Parliament to standardise pilot flying hours were potentially unsafe and would result in more pilot fatigue.
"The European Parliament responded by instructing the European Aviation Safety Agency (EASA) to send the rules to a team of safety experts," said Mr McAuslan.
"Only fatigue experts understand the impact on a body of flying through so many time zones, having consecutive early starts and late duties and all the other factors that make up a pilot's life.
"At the beginning of this year the scientists, some of the most noted fatigue experts in the world, presented their report which concluded that the EU rules were indeed unsafe. But to its shame EASA has ignored this, and is now putting passenger lives at risk."
Balpa claimed that pressure on pilots was growing as competition between airlines became "brutal."
New EU rules due to come into effect in 2012 will see the end of an individual country's ability to set their own higher standards, as currently happens in the UK, said Balpa.
"The UK's Civil Aviation Authority, backed by the UK Government, has previously promised to stick to these standards, whatever Europe says, or change them if science says so.
"The UK has a choice. Bring the rest of Europe up to its standards or join a drive to the bottom. This is a defining moment in how passengers will be protected," said Mr McAuslan.
A Department for Transport spokesman said: "EASA is in the process of considering the responses to its consultation on a first draft of rules establishing flight and duty time limits.
"While these are unlikely to be finalised until some time in 2011, we are confident they will maintain the same high level of safety as the current CAA rules.
"The safety of passengers and crew is our top priority and we will not allow this to be compromised."