Flight restrictions remain in place at Gatwick Airport for a fourth day because of fog, disrupting travel plans for thousands of passengers. More than 20 flights planned for the West Sussex airport on Monday were cancelled in advance and passengers are being warned of delays throughout the day.

Tens of thousands of passengers have had their Christmas travel disrupted in recent days as thick fog has descended on airports.

Thick fog has forced airlines to rip up schedules, causing misery for travelers seeking to escape the winter gloom