We heard earlier from one traveller who praised the CAA's response in helping him return to the UK.

But Matt Rogerson is less impressed with regulator.

"Me, my wife, our 13-month son were supposed to return to LGW from Mahon, Menorca today. Four phone calls to the CAA told us not get our transfer from hotel to airport until a new flight was scheduled. The flight ZB 763 was supposed to leave at 12:40 local time.

"The CAA advertised the new flight details approx 11:25, 75 mins before departure, giving us no time to get to the airport following their instructions to not go to the airport originally (their website and automated phone system says the same thing - don’t go until new flight details confirmed).

"We are now stuck in Ciutadella, checked out of the hotel and don’t know what we’re supposed to do. The CAA haven’t called back despite saying they would. We have nowhere to stay tonight and no idea when we’re going back. Shocking service."

Image source, Getty Images

Monarch's loss is other airlines' gain, it would seem. Shares in easyJet are 4.5% higher at £12.72, while Ryanair shares in London are up 2.5% at £16.67.

IAG, the owner of British Airways, Iberia and Aer Lingus, has added 2% at 605.6p.

About 25 planes from airlines including easyJet and Qatar are being used to bring Monarch passengers back to the UK.

Kimberley from Coventry has been left frustrated and angry after the Monarch's demise.

"My son and his bride-to-be booked their wedding in Paphos Cyprus and were due to fly with Monarch on the 16 October," she tells the BBC.

"The dresses are bought, the rings, the food, the flowers, everything. Guests who have not booked through Monarch will be travelling at great expense to attend a wedding without a bride or groom. My son and his fiancée are in tears. Monarch have destroyed their day."

Image source, Mike Sayer

Mike Sayer says he is "very impressed" with the CAA's organisation after the Monarch collapse.

"I'm travelling back from Barcelona to Manchester with about 250 other passengers going to either Manchester or Birmingham. Information at the airport was good, and while we were delayed as fuel was delivered and paid for a guy from the Foreign Office kept everyone informed.

"We've just boarded and are just about to depart. Could've been so much worse and I'm very grateful for whoever has been coordinating it all - it can't be easy."

Image source, Getty Images

About 860,000 customers are affected by Monarch going into administration, the Civil Aviation Authority says.

The total includes 110,000 who are abroad and 750,000 with future bookings.

The CAA said it had been asked by the Government to charter more than 30 aircraft to bring the passengers home, with Transport Secretary Chris Grayling calling it the "biggest peacetime repatriation" effort.

Natasha Slessor, a former cabin crew member at Monarch Airlines, told the BBC:

“Still can’t believe it really, it’s crazy. I just feel like I’m in a dream, it’s a bit of a shock. We found out when we got the email this morning. We haven’t really been hearing much.

“How can you wake up and not have a job? It’s pretty crazy.

“It was such a shock… there was nothing set in stone until we saw the news last night and thought actually this could be potentially bad.

”We are holding our heads up high, we will all be ok. We are a massive Monarch family and it’s not just a job, it’s our lives.

“We worked with these people on a plane for 18 hours a day sometimes. We knew each other’s lives inside out. So we’ll pull each other through.”

Image source, Greybull

The company was set up in 2012 by Marc and Nathaniel Meyohas and Richard Perlhagen. The idea was to invest the wealth of the two families. The Meyohas brothers are French, but based in London.

Greybull has invested in all sorts of industries. Perhaps the most high-profile investment was the purchase of Tata Steel's Scunthorpe plant in April of last year.

Greybull also took part in the deal to buy 140 convenience stores from Morrisons. That business was put into administration in June 2016, nine months after its purchase.

Image source, PA

Airlines including easyJet, WizzAir, Norwegian and British Airways owner IAG have begun circling what remains of Monarch in the hope of securing some coveted landing slots at airports such as Gatwick and Manchester in particular.

Robin Byde, transport analyst at Cantor Fitzgerald, says that Monarch's assets would be attractive to easyJet in particular.

"Monarch assets may enable easyJet to increase frequencies on common routes, gain more attractive year-round and seasonal slots, and generally take market share. On fleets, synergies could be attractive as Monarch currently operates 34 Airbus A320-family aircraft which are compatible with easyJet's fleet," he explains.

Gerald Khoo, analyst at Liberum, adds: "The pilots are also likely to be in demand, although Monarch's all-Airbus fleet means that they would not be available to relieve Ryanair's shortage (Ryanair operates an all-Boeing fleet)."

Independent travel editor, Simon Calder has a good summary, external of what you should do if you are a Monarch customer.

These pictures are from Tim who recently arrived at Faro Airport, Portugal.

British government officials seem to be there giving out advice.

Emma Hardie emails to clarify a point we made earlier about the origins of Monarch.

She says Monarch was actually started in 1968 by her father, Bill Hodgson, and Don Peacock - former directors of British Eagle - with the financial backing of the Mantegazza family.

The Swiss family backed the airline until 2014, when it was sold to Greybull.

"It is a very sad day for my family and for the big family that was Monarch. There have been generations of families that have worked for Monarch and are still there," Ms Hardie adds.

Image source, Reuters

Jessica from Leicester hoped the cancellation of her Ryanair flight would not mean the end of the her holiday.

"Me and my boyfriend booked a holiday to Barcelona a few months ago. We had quite a small budget so booked a flight there with Monach and flight back with Ryanair," she tells the BBC.

"Less than two weeks ago we got an email from Ryanair to say that our flight was cancelled. We booked return flights at an extra cost of £60 and hoped that was the worst, but on the way to the airport at 4am this morning we got a text from Monach to say 'don't go to the airport, all flights have been cancelled'.

"We've had to rush to book new flights at even more expense and have now lost part of our holiday too."

Moneysavingexpert's Martin Lewis has tweeted his advice for claiming a Monarch refund.

Press Association reporter Alan Jones conveys a couple of interesting points from the union Unite in these tweets:

Asked how long the CAA has been planning the rescue operation, chief executive Andrew Haines said: "We had notification from Monarch four and a half weeks ago that there were issues they were dealing with.

"Unfortunately we didn't get final confirmation until 4am this morning and my understanding is that the board resolution to go into administration didn't take place until close to midnight on Saturday night."

About 410,000 customers are affected by Monarch going into administration, including 110,000 who are abroad and 300,000 with future bookings, the Civil Aviation Authority has said.

Image source, Reuters

Tim Alderslade, chief executive of Airlines UK - the trade body for UK airlines - says it's a "very sad day" for the industry.

"Monarch has been taking British families away on holiday for almost 50 years and has been a well-loved brand and stalwart of UK aviation," he says.

"Our thoughts are with the several thousand employees who face an uncertain future, and the hundreds of thousands of passengers who are currently abroad or have booked a trip and were looking forward to travelling with Monarch.

"Today's news goes to show the ferociously competitive and challenging environment airlines currently operate in. I sincerely hope what has befallen Monarch gives politicians pause for thought about the challenges and costs facing the airline industry."

Joe Alvarez is wondering how to tell his grandmother she might not be able to go to a family wedding.

"I have a flight booked with Monarch to Spain in three weeks time, I was planning to take my elderly grandmother to a family wedding," he says.

"I am now worried that we won't be able to go and she will be very upset. The flights are not Atol protected. They had cost £80 each but other flights are looking really, really expensive.

"I'm really disappointed. I am quite upset that we won't be able to go to the wedding."

A clarification from Martin Lewis on card payments for Monarch flights: