Christmas travellers have been left stranded at the world's busiest international airport in the wake of the snow, with many sleeping in the terminals and lounges.
Heathrow is currently operating a reduced flight schedule, with the south runway remaining closed throughout today and more snow forecast throughout Europe this week.
Lewis PR COO Paul Charles said: 'The UK has again become a laughing stock in terms of transport efficiency.'
Charles, previously comms director at Virgin Atlantic and Eurostar, added: 'Travellers around the world will again be thinking about transiting via other countries, such as France and Germany, which can keep airports and railway stations running in the most intense conditions.
'We just don't seem to have any backup plans or leadership at the highest level.'
The snow chaos has seen airport-owner BAA forced on to the offensive. In an interview with the BBC this morning, BAA's head of media, Andrew Teacher, insisted that things are 'improving slowly', adding: 'People have been put up in thousands of hotel rooms by the airlines.
'It has been a very troubling time for many and we are extremely sorry for the disruption.'
With Arctic conditions paralysing much of the country, Transport Secretary Philip Hammond has also come under fire.
Under the headline 'Ice Rage', this morning's Daily Mirror claimed that Hammond had failed to act on an official report he got in July, outlining how to avoid winter chaos, including the need to stockpile salt.