He furthermore accused Moscow of using the project as a weapon against Ukraine.

“I would expect the new German government to do everything possible not to allow Nord Stream 2 to be an instrument in the arsenal of [Russian] President [Vladimir] Putin,” Morawiecki told dpa in an interview published on Sunday.

The project is becoming a “tool to blackmail Ukraine and Moldova,” he added. “It is also a tool for the manipulation of energy prices.”

The 1,230-kilometre-long pipeline through the Baltic Sea aims to deliver natural gas from Russia to Germany, circumventing Ukraine. Its construction has been completed, but the taps remain closed pending regulatory approval.

Last week, Germany’s Federal Network Agency suspended the certification procedure for the project, citing EU requirements that the pipeline operator must be independent from the gas producer.

The operator, Nord Stream 2 AG, is a subsidiary of the Russian energy giant Gazprom.

A new government coalition in Germany between the Social Democrats (SPD), the Greens and the Free Democrats (FDP) is due to take office in early December.

Their coalition agreement, unveiled on Wednesday, does not directly mention Nord Stream 2. However, it does state that “European energy law also applies to energy policy projects in Germany.”

The wording was especially important to the Greens, according to negotiators, as they are opposed to the project. But the FDP is also sceptical, while the SPD is more open to it.