The companies hoping to run Europe's satellite-navigation system will have to settle their differences soon or risk being shut out of the project.
Mr Barrot and Mr Tiefensee want to prevent further delay
EU transport ministers have set a deadline of 10 May for the squabbling firms to set up a single company structure and appoint its CEO.
It is intended that the Galileo system be built as a partnership between the public and private sectors.
But ministers said delays might force them to look at alternative solutions.
Speaking following an EU Transport Council meeting in Brussels, the German minister Wolfgang Tiefensee reiterated his threat to reopen the tender process if the current consortium failed to adopt a common position on all the financial, technical and managerial decisions needed to make Galileo happen.
"Galileo is in a crisis," he told reporters. "We cannot by any means say that the blockages... have been overcome."
And the EU Transport Commissioner Jacques Barrot added: "If the consortium were not to respond, we would look at all possibilities, including a new call for tender; but we're not at that stage and I feel that this ultimatum will be respected."
If the 10 May deadline was missed, the June Council Meeting would act on the threat, the men stressed.
If that happens, one thought is that the European Space Agency - who already have a stake in Galileo - might temporarily take over the project while new control arrangements are sought.
The consortium is made up of leading aerospace and telecom concerns: EADS, Thales, Inmarsat, Alcatel-Lucent, Finmeccanica, AENA, Hispasat, and TeleOp.
Since 2005, the companies have been trying to seal the details of a deal that would give them a 20-year concession to build and run Galileo.
GALILEO UNDER CONSTRUCTION
A European Commission and European Space Agency project
30 satellites to be launched in batches by end of 2011-12
Will work alongside US GPS and Russian Glonass systems
Promises real-time positioning down to less than a metre
Guaranteed under all but most extreme circumstances
Suitable for safety-critical roles where lives depend on service
But the consortium has failed to agree a common commercial position, and the agency designated by the EU to negotiate for the public sector has suspended discussions with the consortium until the infighting is over.
There are said to be differences over how lucrative contracts should be allocated, and even accusations of political meddling behind the scenes.
Now, EU transport ministers hope to break the impasse by setting out a clear timetable.
By 10 May, they want to see:
- The legal structure for a single operating company put in place
- A chief executive appointed who can talk for the entire consortium without fear of being contradicted by its members
And by September, they also want a signature on the broad terms of the concession.
"I intend to implement these conditions as strictly as possible," said Mr Barrot.
Galileo's technologies are designed to bring greater accuracy and reliability to navigation and timing signals delivered from space.
Analysts expect the system to open up a multi-billion-euro industry in which receivers find their way into many more markets - from consumer mobile devices, such as phones, to safety-critical applications, such as guided trains and buses.
But Galileo has seen frequent slips in its timeline, and there are now fears that unless the concession is resolved soon, the current projected date of 2011/12 for full deployment and operation will be missed.