When Hollywood actor Leonardo DiCaprio hosts a reception for a string of A-list stars, supermodels and wealthy philanthropists later this month, he will make an impassioned plea for more action to be taken on global warming.

But instead of holding the event in Los Angeles, where most of his guests are based, they will fly halfway around the world to the glitzy French resort of St Tropez – at enormous cost to the environment.

Last night, green campaigners were quick to criticise 41-year-old DiCaprio, who in February used his Best Actor acceptance speech at the Oscars to warn about the dangers posed by climate change.

Leonardo DiCaprio (left) is clearly passionate about global warming. Last year Kelly Rohrbach (left) and Kate Hudson (right) were among those invited to the foundation's gala in the south of France

The reception – the grand-sounding Leonardo DiCaprio Foundation Annual Gala To Fund Climate and Biodiversity Projects – will be held on July 20 at the Bertaud Belieu Vineyards on the French Riviera.

Celebrities including Kate Hudson, Charlize Theron, Cate Blanchett, Marion Cotillard, Penelope Cruz, Robert De Niro, Scarlett Johansson, Arnold Schwarzenegger and Kevin Spacey are all expected to attend, along with a host of international rock and pop stars, supermodels and tycoons.

And while a table seating 12 people at the gala costs up to £125,000, the real price will be paid by the environment.

If just one guest among the 500 invitees chooses to fly the 12,000-mile round trip from LA to St Tropez by private jet – a notoriously environmentally unfriendly way to travel – they will produce 86 tons of carbon dioxide greenhouse gas.

Even those who use a scheduled flight will be responsible for releasing seven tons of CO2 – leading green campaigners to ask why the event could not have been held in Hollywood or in St Tropez during May’s Cannes Film Festival, when many of the guests would have been there anyway.

Robert Rapier, an environmental analyst, said: ‘DiCaprio demonstrates why our consumption of fossil fuels continues to grow. It’s because everyone loves the combination of cost and convenience they offer.

'He believes that no sacrifice is necessary; just Government policies that can provide him with a solar-powered yacht or jet, or that give individuals low-cost renewable energy on a broad scale.’

Experts say if the guests travel by scheduled flight they will produce seven tons of carbon dioxide per person, while if they travel by private jet it would be nearer 86 tons

One guest who attended last year’s gala said: ‘It’s basically a big party for Leo and his showbusiness friends and models. The models, of course, do not pay for tickets, and neither do the VIP guests – they get to have a nice big free party.’

The Mail on Sunday has learned that guests opting for the Grand Earth Protector Package – ‘prime dinner seating for 12 guests’ at a table near to DiCaprio – costs £125,000. The more frugal Earth Protector Package – seating 12 at a slightly more distant table – costs £82,000, while those content with social Siberia can choose the Ocean Steward Package, at a mere £58,000 for 12 diners.

The Titanic star – whose love of private jets is well known – has long been dogged by accusations that he fails to practise the carbon footprint-aware lifestyle he preaches.

In May, he flew by private jet to New York from France, where he had been attending the Cannes Film Festival, to receive a ‘green’ award – before flying back the following day.

The 8,000-mile round-trip churned 55 tons of CO2 into the atmosphere. In the previous five months, he travelled more than 91,000 miles by plane during 18 separate trips.

Where private jets are used, the carbon dioxide emitted goes up hugely – between seven and 20 times, depending on the plane.

It is estimated DiCaprio has potentially emitted up to 418 tons of CO2 this year alone because of his globe-trotting. In contrast, the average American produces just 19 tons on flights each year.

The Leonardo DiCaprio Foundation gala was first held in 2014 (pictured) at Domaine Bertaud Belieu in St Tropez and has become an annual event

In 2014, emails hacked from film studio Sony revealed the actor took six private flights in just six weeks, costing £138,000, though a friend insists most of his journeys were commercial.

DiCaprio – who sits on the boards of two eco-pressure groups – has previously made much of his support for environmental causes, with his foundation recently pledging more than £10 million to green projects at this year’s World Economic Forum.

In 2008 he made his own environmental documentary, The 11th Hour, which inconveniently tanked at the box office.