Advance warnings about a step-up in airport security meant passengers at London's Heathrow experienced a smooth start to their journeys yesterday.

Queues for flights to the US from Terminal 3 were relatively short and holidaymakers appeared pleasantly surprised by the lack of complications.

Those who had arrived early for fear of delays at check-in said they appeared to have made needless effort.

Company owner Mary Lecarpentier (45), from Southampton, who was travelling to New York to celebrate New Year, said: “I've only just joined this queue and it's fine, I'm nearly there.

“It's Christmas as well so you'd expect some delays but there really haven't been any so far.

“I'm not worried at all. Sometimes there are delays and you just deal with them but we haven't experienced any.”

Another passenger, flying home to Boston, said she had arrived early for a 2pm flight to allow for potential delays.

Marta Ostovich (28), an archaeology student who was returning from a two-week holiday, said: “I came well in advance because I was worried but I think I came needlessly early as it seems to be OK.

“My flight looks like it will be leaving on time — it's definitely not as bad as I thought it would be.”

Meanwhile, professional sailor Alain Sign (23), from Portsmouth, who was on his way to the Bahamas via Miami, said the initial part of his journey had been “easy”.

He said: “I wasn't really concerned and the queue seems to be the same as it usually is so it has been easy so far.”

A spokesman for British Airways said passengers were still being warned about changes to the hand baggage allowance ahead of travel.

Meanwhile passengers travelling with Virgin Atlantic were advised to arrive at the boarding gate early to minimise delays.