Talks to head off strike action and passenger chaos at Heathrow are due to begin today.

The Unite union, which represents thousands of airport workers including security guards and firefighters, has strikes planned for January 7 and 14 in the dispute over BAA closing its final salary pension to new employees.

Heathrow and Gatwick and five other BAA airports would be affected by the strike, which the operator calls "unnecessary".

Unite says the pension decision is being forced on BAA by its Spanish owners while the operator says the changes do not affect existing workers so the strike should be called off.

The strike dates follow an announcement that Virgin Atlantic cabin crew will walk off the job in two 48-hour stoppages in January in a dispute over pay.

Passengers already face increased disruption on January 7, the first day of new rules allowing flyers to carry on two pieces of hand luggage.