Artists have been urged to take a stand against ‘extortionate’ concert prices after Oasis ticket prices more than doubled.

Fans of the Manchester band have expressed their shock and anger after queuing online for hours only to discover that the price of a standing room ticket had risen from £135 to £355.

House of Commons leader Lucy Powell said she had paid “more than I expected” and did not like the so-called dynamic pricing model, which allows ticketing websites to increase prices based on demand.

Powell said she is “not sure how fully transparent” the process is after hundreds of thousands of fans waited for tickets based on prices announced last week.

Fans only discovered at the point of purchase, after waiting in an online queue for hours, that standing tickets were available, described as “in demand” – priced at £337.50 plus fees. These offer the same as the basic £135 tickets, despite costing more than double.

Ticketmaster, which is owned by US entertainment giant Live Nation, defended its dynamic pricing model – similar to that used by hotels and airlines – and said it did not set ticket prices.

The company has argued that the system is designed to discourage ticket sellers by setting prices closer to market value. The company says that the “on demand” rates are agreed in advance with artists and their management.

Lib Dem culture spokesman Jamie Stone MP said: “It is outrageous to see our country’s greatest cultural moments being turned into obscene cash cows by greedy promoters and ticketing websites. The Oasis ticket debacle must be a turning point and lead to an official investigation, either by the watchdog or a parliamentary body.”

Labour has pledged in its manifesto to tackle ticketing, where secondary websites sell tickets at excessively high prices. The party will launch a consultation on this in the autumn.

In Ireland, fans looking to buy a ticket for a concert at Oasis’ Croke Park costing €86.50 (£73) were faced with a price of €415.50 for the same ticket.

Regina Doherty, a Member of the European Parliament for the Dublin constituency, called for an investigation into the prices which she said were not “transparent advertising and certainly not fair to consumers”. She added: “Every ticket for these gigs would always be ‘in demand’ so slapping an extra label and €300 on a number of standing places is simply excessive.”

The European Commission, the European Union’s executive arm, said last year that it was “aware of concerns” about ticketing websites using dynamic pricing and that it was “monitoring the situation”.

The commission said the “imposition of excessive prices by a dominant company” would be a breach of EU law.

Earlier this year, the U.S. Department of Justice announced that it would sue Live Nation for “monopolization and other unlawful conduct that impedes competition in markets in the live entertainment industry.”

Jonathan Brown, the CEO of the Society of Ticket Agents and Retailers, defended the dynamic pricing policy, stressing that prices were set by artists. He said people were “used to” the price shift, likening it to booking a hotel or a trip.

But John Robb, the musician and writer, said it “exploited people’s enthusiasm in the worst possible way… We need the government to look at this, and we need to stop people being ripped off.”

Sean Adams, manager of artists including Charlotte Church and The Anchoress and founder of music website Drowned in Sound, called on MPs to investigate dynamic pricing but said “change really has to come from artists”.

He added: “Why is a ‘group of the people’ going along with this dynamic corporate ticketing policy that feels like it is ripping off fans who had just as much chance of being in the digital queue as anyone else?”

Dozens of Oasis fans complained that they were not warned that prices could rise if they were at the front of the queue.

Prof Michael Waterson, who was appointed by the previous government in 2016 to review anti-touting measures, said it was particularly important for ticket companies to be transparent about prices up front. “You can then think about whether you are prepared to pay higher amounts and it is less of a surprise,” he said.

Under UK consumer law, businesses must be transparent about the prices they charge and must not mislead customers, for example by providing incorrect or misleading information, or by omitting or providing important information late.

The Competition and Markets Authority said it could not comment on individual cases.

Ticketing and security expert Reg Walker, who works with major music venues, said Ticketmaster would ultimately emerge as a major beneficiary of the higher fees. “The reason they’re pushing it (dynamic pricing) is if you sell a ticket for £100, with a 10% service charge, you get £10. If you sell it for £400, you get £40.

“So it’s in Ticketmaster’s interest to push this model. I’m not convinced artists know what they’re getting into.”

The Guardian has reached out to Ticketmaster and representatives for Oasis for comment.