The closure of airspace in the Netherlands and southeast Britain due to volcanic ash from Iceland will cause the cancellation of about 1,000 flights.
The volcano under the Eyjafjallajokull glacier has been erupting since April with no sign of the activity about to end. The ash plume has reached heights of 7,620 metres, according to Britain's Meteorological Office.
The latest ash cloud is forecast to partially to disperse on Monday but it is expected to affect Northern Ireland, parts of Scotland and parts of southwest Britain later, according to European air traffic agency Eurocontrol.
Although 1,000 flights have been cancelled, another 28,000 are expected to go ahead.
Passengers using some of Britain's busiest airports are facing major disruption. Heathrow, Gatwick and London City airports resumed limited flights on Monday after being closed from 1am until 7am local time, the BBC reports.
However, passengers are being urged to check with their airlines before travelling. Restrictions are expected in parts of the United Kingdom until Tuesday.
A spokesman for air traffic authority, Nats, said Gatwick was due to be closed to arrivals until 1pm local time and departures would be subject to restrictions.
Eurocontrol said Heathrow arrivals would be limited to 30 an hour initially and warned of significant delays.
In the Netherlands, airports in Amsterdam and Rotterdam closed for at least eight hours on Monday.
Railway companies laid on extra trains to cope with increased passenger levels including Eurostar, which said it would operate extra trains between Paris and London.
Ash from the volcano has already caused considerable disruption over Europe since April, forcing airlines to cancel about 100,000 flights and stranding millions of passengers.
The ash contains tiny particles of glass and pulverised rock that can damage engines and the mechanical structure of planes.
New Zealand flights
Air New Zealand flight NZ39 Auckland to Hong Kong and London, and flight NZ2 Auckland to Los Angeles and London are still operating as scheduled on Monday.
However, they may be disrupted at Hong Kong and Los Angeles, respectively, should the airspace remain closed.
Other Air New Zealand flights are delayed in London and Los Angeles.
Travel agency House of Travel says people planning overseas holidays need to be flexible and may have to change their itineraries to suit the situation.
Retail director Brent Thomas says customers should stay in close contact with their travel agent to get the most up-to-date information about flights.