Monarch says it will start rewarding passengers for being polite with free upgrades — but subject to some intricate terms and conditions.

The airline, which was saved from the verge of bankruptcy last autumn, has embarked on a “year-long campaign to promote traditional values of chivalry, courtesy and respect”.

Monarch’s chief operating officer, Nils Christy, said: “We are often described as the nicer airline and holiday company and we pride ourselves on this.

“Our customer services staff are already nice – now they can reward those who are positively nice to them too.”

Call-centre staff will be able to award polite passengers with either extra-legroom seats, normally costing £20 or £30, or priority check-in — worth a mere £3.

The airline says it is “following in the footsteps of Pret a Manger”. Staff at the restaurant chain hand out around 20,000 free drinks each week as random acts of kindness to customers.

But Monarch will upgrade a maximum of 10 bookings per week. As all passengers on a single reservation will receive the award, in a typical week around 25 people will benefit, out of the 120,000 who fly with the airline.

The upgrades will be only offered to passengers who want to buy tickets by phone (costing £7.50 per person per flight above the web fare) or have an issue and need to talk to someone at the airline. No-one who transacts only online with Monarch or via a travel agent will qualify.

The initiative follows research conducted by Professor Jonathan Freeman at Goldmiths’ College in London in which subjects were shown a sequence of video images — such as an overcrowded Tube platform, a traffic jam or a screaming child — while their facial reaction was measured.

“Monarch employees tended to score a little higher on emotional intelligence than the rest of the subjects,” said Professor Freeman.

“They also scored significantly higher on agreeableness and empathy.”

One possible problem for the new scheme is getting through to the call centre in the first place. Yesterday a passenger named Tracey Burrows tweeted "@Monarch please can someone answer the phone!!", and later said she had been hanging on all afternoon.