It was “pointless” to hold a meeting on the increasingly unpopular fuel without Europe's largest car-manufacturing country present, Bienkowska told business newspaper Handelsblatt, adding that Scheuer's cancellation was “disappointing”.
In Berlin, the German minister said a diary clash he had let Brussels know about long in advance held him back from attending.
“I didn't know anything about this diesel summit…we can keep talking about diesel in Europe, just on a different day,” Scheuer said in a video uploaded by the transport ministry.
In a statement, the Commission said that given few ministers planned to attend, the meeting would be “conducted at a technical, services level, with a similar agenda”.
Politicians across Europe fear the proliferation of planned or already implemented driving bans for older diesels in cities, put into place to clean up polluted air of harmful fine particles and gaseous nitrogen oxides (NOx).
Under pressure from the Commission, Berlin presented a “diesel plan” in early October supposed to satisfy air quality concerns while limiting driving bans, which are widely resented by drivers.
It calls for trade-in bonuses for older diesels or hardware refits to bring them up to the latest emissions standards – with the former option the clear preference of the auto industry, a vital sector for Germany that employs 800,000 people.
Governments and the Commission are also looking to promote alternatives to the internal combustion engine, as the EU aims to slash carbon dioxide emissions from cars 40 percent by 2030.