A £20 million fund and a new review board has been announced in a drive to improve Southern rail services and "get to grips" with problems on its network.
The Government unveiled a series of measures, including the appointment of a new "project board", following months of disruption to Southern services because of a bitter dispute over the role of guards, and staff shortages.
Former Virgin Rail chief operating officer Chris Gibb will head the new board, working with the train operator, the Department of Transport and Network Rail, to look at achieving a "rapid" improvement in services.
Transport Secretary Chris Grayling said: "I want the Southern network to be run by a team of people who work together to make sure passengers get decent journeys and that problems are dealt with quickly. This review will suggest how we achieve a joined-up approach to running the train and tracks and make things work better for the public.
"We also need to get to grips with things that go wrong on this part of the network. That is why we are putting in place a £20 million scheme to tackle the cause of breakdowns that too often cause frustrating and damaging delays on the network.
"I now urge the industry, the train operating company and unions to work together to improve services for passengers."
The Transport Department said the package of measures follows months of "unacceptable disruption" for passengers.
Mr Gibb, currently a non-executive director at Network Rail, said: "I look forward to helping the rail industry improve the passenger experience on the Southern network.
"Committed railway people across the industry work hard round the clock to provide the best possible service to a growing number of passengers, during a time of much-needed major investment.
"I will bring together the energy of these people to find ways to improve the delivery of this service in the short and medium term."
The package includes £2 million to be spent on more rapid response teams to fix faults more quickly, located close to known hotspots; £2.5 million on accelerated train maintenance; £800,000 investment in extra signal supervisors; and £900,000 in a series of measures to minimise the impact of bridge strikes.
Charles Horton, chief executive of Southern's owner, Govia Thameslink Railway, said: "We welcome the benefits this £20 million improvement package will bring for passengers, tackling some of the key infrastructure challenges on the network.
"Network Rail and Southern will continue to work closely together to ensure this investment delivers real, tangible benefits for our passengers and the new project board will ensure the programme is effectively delivered.
"This investment complements our existing programme of improvements which is bringing in new trains and changing working practices to improve customer service."
Anthony Smith, chief executive of watchdog Transport Focus, said: "Passengers will welcome a firmer grip being taken. Continuing poor performance has eroded their trust in the railway.
"To start rebuilding that trust we want to see an honest, realistic plan that leads to a return of reliable services, and better compensation for the months of misery they have experienced."
Rail, Maritime and Transport union general secretary Mick Cash said: "This stinks of another multimillion-pound taxpayer subsidy to bail out the failing Southern rail part of the Govia Thameslink franchise.
"If there's money to prop up this private outfit, why isn't there cash available to make sure that the guards and safety are protected on their trains?
"If this huge chunk of money was allocated to maintaining the safety-critical role and the jobs of the train guards on the Southern services, we could have avoided the strike action that has been forced on us again next week by the penny-pinching, profiteering and intransigence of Southern/GTR."
Phil Hufton, Network Rail's managing director for England and Wales, said: "We are committed to working closely with GTR to improve overall performance. We are already working hard together to minimise delays and disruption to passengers and are of course keen to do as much as we can to improve services.
"I welcome the appointment of Chris Gibb to the role and know that his experience and insights can help us all in our efforts to raise performance across the Southern area."
Louise Ellman, who chairs the Transport Select Committee, welcomed the news, adding: "The passengers who use this line day in, day out are entitled to feel angry. The situation has been unacceptable for over a year now.
"Southern passengers deserve a rapid improvement in their service. The Transport Committee will continue to monitor the situation to see if this brings any real change."
TSSA general secretary Manuel Cortes said: "As Southern is the largest franchise in the network and working at 279% over-capacity, £20 million is a mere fragment of the amount needed to upgrade the service so it is fit for the purpose commuters in the South East so desperately need.
"Chris Grayling and Chris Gibb are both calling for closer co-operation with unions to improve the service offered to passengers.
"If they aren't weasel words, TSSA will be delighted to take them up on the offer and I look forward to receiving a formal invitation.
"We'll start by telling the DfT that the only meaningful way forward for Southern passengers to be given a reliable service is to take the franchise back into public control."