The government has blocked relaxation of a ban on carrying liquids in airline hand luggage amid warnings from carriers that the move would trigger chaos at airports.

The transport secretary, Philip Hammond, has told UK airport owners that the first phase in lifting restrictions will not go ahead as planned on 29 April. Passengers on long-haul flights from outside the European Union would have been allowed to carry duty-free liquids on to connecting flights at EU airports. Airlines and airport groups have warned that the proposal would lead to severe delays because terminals might not have adequate screening equipment, while some countries such as France and Italy are considering ignoring the 29 April deadline.

In a letter to airport owners yesterday, Hammond said the ban would remain. He cited security concerns as the reason for the delay. A government source said: "The EU regulation will still come into force but, because of current security conditions, we are imposing stricter measures that mean, effectively, there will be no change." The new UK security measures are expected to remain in place for at least six months.

The Airline Operators Association has lobbied for a hiatus in the partial lifting of the liquids ban after warning that the x-ray technology to detect suspect liquids is not ready. Darren Caplan, chief executive of the association, said. "Airports have always supported a lifting of the ban for the benefit of our passengers, to ensure they have a positive experience when they are travelling – but only when appropriate technology has been developed and properly tested."

The EU now faces calls to issue a new timetable for lifting the ban, given the UK's important role in the transfer passenger market – Heathrow carries around 6 million connecting customers from outside the EU every year. For instance, if the ban is lifted in Germany, passengers transferring through Frankfurt airport will be allowed to keep their duty-free purchases while travellers using Heathrow will be forced to bin bottles of alcohol or perfume. Under the full EU schedule, all restrictions on carrying liquids will be lifted by April 2013.

Current rules bar all passengers from carrying liquids on to planes unless they are in individual containers no bigger than 100ml. Introduced across Europe in the wake of the Heathrow bomb plot in 2006, the ban has left mounds of water bottles and perfume sprays at terminals across the continent. At Heathrow 2,000 tonnes of liquids are confiscated every year.

Manufacturers of airport security equipment maintain there is the technology available to support a complete lifting of the ban. They argue that their machines, which are in wide use across the continent, require just a software upgrade to be capable of detecting liquids that could be explosive.