Afp, FRANKFURT AM MAIN: Ukrainian President Petro Poroshenko on Monday urged Germany to abandon plans to build a controversial second pipeline to bring gas from Russia, saying it would enable a "blockade" against his country.

The Nord Stream 2 project is "political bribe money for loyalty to Russia," Poroshenko told German business newspaper Handelsblatt.

Building it would mean "imposing an economic and energy blockade on Ukraine" he added, charging that the pipeline has "no economic justification".

German Chancellor Angela Merkel has called Nord Stream 2 a purely "economic project" with no need for political intervention, but it has become an open wound in relations with eastern neighbours and the European Commission.

The pipeline would double the amount of Russian gas arriving in the European Union's most powerful economy via the Baltic Sea -- without transiting Ukraine -- by late 2019.

Authorities in Germany issued the final permits needed for construction of Nord Stream 2 on its territory and in its waters to begin last month, although other nations' green lights are still needed.

But "the Ukrainian transit pipeline is much cheaper and can be modernised cheaply and easily," Poroshenko told Handelsblatt.

He accused Russia of being an "extremely unreliable partner" in energy provision, pointing to state-owned energy firm Gazprom's refusal to pay Ukraine billions of euros after shutting off gas supplies in the middle of winter.

Gazprom accounts for around one third of Europe's gas supply.

Less and less has arrived via Ukraine in recent years, part of Moscow's conflict with its former satellite which saw Russia annex the Crimean peninsula in 2014 -- prompting EU sanctions in response.