A coalition of MPs and peers from a host of different parties is using the European court of human rights to challenge an alleged failure to investigate Russian interference in UK elections.

The legal action has been launched in response to the UK government’s refusal to order an inquiry into the findings of the Russia report, published by the intelligence and security committee (ISC) in July 2020, which reported credible evidence of attempts by Russia to interfere with the UK’s electoral processes.

The parliamentary group bringing the action includes the Labour MP Ben Bradshaw, the former leader of the Green party Caroline Lucas, the SNP MP Alyn Smith, Lord Strasburger of the Lib Dems and the former Tory peer Lady Wheatcroft.

The group claims the government is in breach of article 3 of the first protocol to the European convention on human rights, which requires regular, free, secret-ballot elections to “ensure the free expression of the opinion of the people”.

Lucas, the MP for Brighton Pavilion, said: “As President Putin wages a war of terror on the Ukrainian people, he’s been waging another war on the very principles of democracy.

“The Russia report is clear that there is credible evidence of Russian interference in UK electoral process – and yet our government has consistently refused to investigate these serious conclusions.”

The Russia report declared Russian interference in the UK “the new normal” and reported credible attempts to interfere with the UK’s electoral processes from at least the time of the EU referendum in 2016.

The ISC called for an investigation and an updated legal and institutional framework to protect those processes from foreign interference.

When the government did not act on these recommendations, the cross-parliamentary group joined forces with the non-profit journalism organisation the Citizens to file an application for judicial review in August 2020. Permission for judicial review was refused by the high court and the group’s application for permission to appeal was turned down by the court of appeal.

Lucas said: “We now have no other option than to take our case to the European court of human rights, in order to try to force the government to undertake a full investigation into the evidence, or else we jeopardise the free and fair elections we hold dear and allow Putin to believe that, once again, he can get away with hostile state interference in our democratic processes.”

Strasburger said: “For some time it has been obvious that Putin has infiltrated the British establishment and our government. Predictably Boris Johnson delayed publication of the Russia report as long as he could and then ignored its excellent recommendations.

“Likewise he declined to tackle the tsunami of dirty money the Russian oligarchs have been allowed to launder in London and only moved against them when the Ukraine crisis meant he had no choice.

“Even then he did as little as he could get away with and gave the oligarchs ample time to spirit their assets out of the country. It’s high time to deal with this vipers’ nest and hopefully this legal action will lead to full exposure.”

The long-delayed Russia report found the British government and intelligence agencies failed to conduct any proper assessment of Kremlin attempts to interfere with the 2016 Brexit referendum.

It said the government “had not seen or sought evidence of successful interference in UK democratic processes” at the time, and it made clear that no serious effort was made to do so.