By Claire West

British Airways is rebuilding its operations after five days of very severe disruption at its Heathrow home as it tries to fly tens of thousands of disrupted customers ahead of Christmas Day.

Heathrow was shut for most of the weekend as a result of the snow and the airline has been forced to cancel more than 2000 flights in the past six days during one of busiest travel times of the year.

Over the weekend the airline had to divert more than 40 fully loaded longhaul aircraft to airports across Iceland, Spain, Cyprus, France, Greece, Ireland, Germany, Switzerland and many regional airports across the UK.

As airports such as Frankfurt, Amsterdam, Paris and Brussels and several others were forced to close across Europe, around half of the shorthaul Airbus fleet at Heathrow also became stuck at the wrong airports.

This has led to severe disruption to the rosters of 14,000 cabin crew and more than 3,000 pilots which all need to be redesigned so that the airline has enough crew to operate its flying schedule over the entire Christmas and New Year period.

Today, Thursday December 23 and Tomorrow, Friday December 24 the airline is hoping to operate its full longhaul departure schedule from Heathrow. It will also operate a normal schedule at Gatwick and London City airports.

The airline aims to operate the vast majority of shorthaul flights to and from Heathrow and is looking to increase the number of seats by flying larger longhaul aircraft to European cities where possible. On Wednesday the airline flew 275 seater Boeing 777s to Paris, Barcelona, Amsterdam and Madrid to help clear the backlogs.

Customers should check their bookings on www.ba.com to see if their flight is still operating before leaving for the airport. If their flight has been cancelled they should not come to the airport but contact British Airways or their travel agent.

Customers in the UK wishing to rebook their flights can contact the airline on 0800 727 800 which is a free telephone line.

British Airways is also hiring in extra aircraft and is increasing shorthaul seat numbers at Gatwick and London City to several European and UK destinations, which are also served at Heathrow.

In an attempt to free up even more seats, the airline is continuing to encourage customers who hold bookings to or from Heathrow up until the end of New Years Eve to either rebook for a later date or claim a full refund if their journey is not essential.

Willie Walsh, British Airways chief executive, said: "I am very sorry for all the disruption and inconvenience that our customers have faced around the world in the past few days.

"Our teams are working around the clock to get as many people where they want to be ahead of Christmas Day and we are doing all we can to increase the number of seats available.

"We typically spend six weeks pulling together the complex Christmas rosters for our 14,000 cabin crew and more than 3,000 pilots. Those 17,000 rosters are like a giant global jigsaw puzzle, which has been torn up by the"We typically spend six weeks pulling together the complex Christmas rosters for our 14,000 cabin crew and more than 3,000 pilots. Those 17,000 rosters are like a giant global jigsaw puzzle, which has been torn up by the days of disruption at Heathrow and around the world. We now have around a day to rebuild those rosters, so that we get the maximum number of flights into the air ahead of Christmas.

"This is a huge logistical task but we won't stop working until we fill our aircraft with as many customers as possible."