Chaos gripped London’s commuter trains yesterday as the launch of a new private rail mega-franchise spectacularly backfired.

Tory transport minister Claire Perry was berated by boisterous commuters at London’s Blackfriars station as she cut the ribbon for the new Govia Thameslink, Southern and Great Northern franchise on Monday morning and passengers took to Twitter to voice their discontent.

The new mammoth company, part-owned by the French state, takes over the Bedford to Brighton Thameslink line and trains to Hertfordshire and Cambridge from FirstGroup. It also takes on commuter lines from Hampshire, Sussex and Surrey which were already operated by Govia under the Southern franchise.

Last week ministers sneakily extended Govia’s Southeastern franchise to 2018. A rail union source told the Star that the Con-Dems were attempting to wreck the possibility of an incoming Labour government taking franchises back into public ownership as they expire.

But in London yesterday the wheels began to fall off within hours of the launch. The breakdown of a train at Moorgate caused severe delays and this was followed by signalling chaos at London Bridge.

Ms Perry, a former banker, was confronted by angry passengers and rail union members protesting against fare rises and staffing cuts.

One besuited man squared up to her on the platform at Blackfriars, berating her over disruption.

Aslef general secretary Mick Whelan blasted the government’s “rewards for failure” transport policy.

“We were told that privatisation would bring about improvements thanks to competition,” he told the Star.

“We knew this was complete and utter nonsense at the time.

“We need to put the wheels and the steel back together — under public ownership.”

RMT acting general secretary Mick Cash said unions would pursue a “rolling campaign” against the franchisee’s threat of driver-only operation and booking office closures.

“Passengers can now expect to see fares go up and a less safe service as the franchisee tries to squeeze as much profit as it can from the operation,” he said.

Cheaper fares between stations formerly served by both Southern and FirstGroup will be scrapped.

“The government’s plans for secret fare rises in the south-east will leave commuters hundreds of pounds out of pocket,” said Labour shadow transport secretary Mary Creagh.