Germany says legal action by Switzerland's national airline, Swiss, aimed at scuppering a bilateral aviation deal, has no hope of getting off the ground.
Swiss says the accord, due to come into force at the end of the month, will lead to major disruption in air traffic at its Zurich Airport hub.
"We are not concerned," said a spokesperson for the German transport ministry, "because we don't give their case any chance of success."
Swiss - in conjunction with the operator of Zurich Airport, Unique - had earlier lodged a complaint against the accord with the administrative court in Baden-Wurtemberg, a German state which borders Switzerland.
The complaint centres on restrictions to weekend flights which are due to come into force on October 27, even though both Switzerland and Germany have yet to ratify the accord.
Under the terms of the accord, weekend flights between 2000 and 0900 will be prohibited. They are currently banned between 2200 and 0600.
Swiss spokeswoman, Christine Bühler, said certain parts of the agreement contained "discriminatory measures".
She added that limitations on take-off and landing times could reduce flight capacities by between 25 and 30 per cent.
Bühler said this could result in major disruption to air traffic at Zurich Airport, causing severe delays.
Noise pollution dispute
The air transport accord is aimed at ending a long-running dispute between Germany and Switzerland over noise pollution.
Residents in southern Germany have complained for years about noise pollution from flights operating out of Zurich Airport, which lies less than 20 kilometres from the German border.
This led the two countries to hammer out an agreement to cut by a third the number of flights permitted to use airspace over southern Germany before landing at Zurich airport, from 150,000 to 100,000 flights per year.
The deal also includes a ban on night flights and a reduction in weekend aircraft movements.
But in June, the German parliament refused to ratify the accord, just one day after it was rejected by their counterparts in Bern.
swissinfo with agencies
From October 27, weekend flights out of Zurich will be prohibited between 8pm and 9am.
Since 2001, a ban on flights between 10pm and 6am has been in operation.
Swiss fears the aviation accord could reduce flight capacities by up to 35%, as well as disrupt air traffic and cause long delays.