Five young people will on Tuesday file a lawsuit against 12 European governments over an international pact that allows fossil fuel investors to sue countries for taking action to tackle climate change.

Originally drawn up to support energy sector investments in former members of the Soviet Union, the Energy Charter Treaty (ECT) allows investors to sue countries over policies that damage their investments, and has been branded an obstacle to climate action by campaigners.

The plaintiffs represent countries hit by recent climate change-related disasters including Germany and Belgium, which last year suffered devastating floods after heavy rain that scientists said was made more likely by climate change.

Their suit will ask the European Court of Human Rights to protect their rights by ordering governments to remove impediments to fighting climate change created by the ECT.

The case targets Austria, Belgium, Cyprus, Denmark, France, Germany, Greece, Luxembourg, Netherlands, Sweden, Switzerland and Britain, all of which are ECT signatories.

"Governments are still putting profits of the fossil fuel industry over human rights. But climate change is escalating and demanding more and more lives every day," 17-year-old student Julia, one of the plaintiffs, said in a statement.

The more than 50 signatories to the ECT are currently negotiating reforms to it, but countries including Spain and France have raised the possibility of EU countries leaving the accord amid a lack of progress in the talks.

Criticism of the treaty has intensified amid lawsuits from companies seeking compensation for fossil fuel assets. RWE last year used it to seek compensation from the Dutch government over its plan to phase out coal-fuelled power by 2030, which would affect the German utility's Eemshaven power plant.