By Marian Hens
BBC News, Madrid
One of the most prestigious events in the international oil and gas industry, the World Petroleum Congress (WPC), is opening in Madrid.
It comes at a time when Spain's economy is suffering from the record oil prices that show few signs of cooling.
Under the motto, "A world in transition: delivering energy for sustainable growth," the Congress - often referred to as the Olympics of the oil industry - is expected to attract more than 4,000 delegates from 60 countries.
Delegates will include energy ministers and key decision-makers from the largest oil companies, such as BP, Royal Dutch Shell, Exxon Mobil and Gazprom.
"We are a unique forum, because our membership represents over 95% of the world oil and gas production," Dr Pierce Riemer, WPC's director general, told the BBC.
"Madrid will be our largest event ever. Oil prices will be a focus, but also climate change, water and young people."
Jorge Segrelles, president of the Spanish organising committee, said: "Madrid should be proud to host this meeting at a time when oil has taken centre stage worldwide."
Food price anger
But not everyone is happy that Spain is hosting the event.
Spanish consumers are still under shock after thousands of truck drivers went on a massive strike earlier this month, demanding government compensation for losses caused by the soaring price of fuel.
They have seen their businesses affected as fuel prices have increased by 20% since the beginning of the year.
The protest disrupted deliveries, caused shortages of fresh food in supermakets and, coupled with a fishing strike, left fish stalls bare.
Tempers ran high during the Spanish truckers' strike
The crisis came off the back of a sharp increase in food prices, which has been a blow to many Spanish households.
Food price inflation in the country is currently the highest in the eurozone, with flour, milk and sunflower oil prices rising by between 20% and 40% during the last year.
Oil prices have helped push the country's official inflation rate to 4%, the highest level for 10 years and well above the rate expected by Economy Minister Pedro Solbes.
"Spaniards are already feeling the pinch of a tumbling housing market and higher interest rates," says Jaime Pastor, of Madrid's Autonoma University.
"In addition, the government has recently proposed an increase in electricity bills of over 5% on average. The energy crisis could escalate into a social crisis," he adds.
"Many Spaniards are resenting the oil lobbies and they won't be so pleased to see them gather in Madrid."
Indeed, dozens of Spanish civic platforms have got together under the umbrella of Esap (Encuentro Social Alternativo al Petróleo) and plan to stage an "alternative" congress in Madrid which will feature talks, music events, and "peaceful actions" directed against the WPC.
"An energy model based on petrol is unsustainable," says Jose Luis de la Flor, an Esap activist. "But the oil industry is very lucrative. It is reaping the planet's depleted resources. We think the WPC's talk around sustainability is cosmetic."
The WPC's Dr Riemer says that the meeting is trying to be inclusive and looks to reflect all arguments.
"We have tried over the years to do things differently and we invite all the stakeholders. Nobody is excluded," he says.
"We have top people from NGOs, like Transparency International, speaking at the Madrid event.
"The majority of topics in this 19th edition have to do with the environment and social responsibility, something we take very seriously," he says.
But Spanish activists remain unconvinced. They have already called on "Madrilenos" to take to the streets on their bikes on Saturday to "welcome" the oil delegates.