European space boss Jean-Jacques Dordain on Wednesday called on the next-generation Ariane 6 rocket to be deployed "as swiftly as possible" and preferably before 2020.

Quizzed by the European Affairs Commission in the National Assembly, the lower house of the French parliament, Dordain urged European space ministers to press ahead vigorously with the programme when they meet in Luxembourg in early December.

"As far as I am concerned, we need to have an Ariane 6 available as swiftly as possible, and if possible before 2020," he said.

Dordain, director general of the European Space Agency (ESA), described the Ariane 6 as being of "strategic value" for Europe, capable of meeting demands for satellite launches from governments and the private sector.

ESA's mainstay launcher is the Ariane 5, a heavy rocket that is highly reliable but is heavily subsidised -- it has to carry two large satellites to be profitable.

Many analysts say the satellite market is evolving fast towards smaller, single launch payloads, which favours a new breed of US space entrepreneurs.

In November 2013, ESA ministers gave political approval to Ariane 6, sketched as a low-cost flexible successor able to place a single payload of three to 6.5 tonnes into a geostationary slot.

The three-stage design was approved last July, amid expectations of a maiden flight in 2021 or 2022.

ESA also plans to tweak the Ariane 5 with an ME version -- for Midlife Evolution -- that would be ready by 2017 and yield operational savings over the existing ECA and ES models.

The ME is being backed by Germany.

The twin schemes have caused tensions.

France's national auditor disclosed in February that French policymakers favoured dropping the ME to keep down development costs and prevent a feared delay to Ariane 6.