Nadezhda Tolokonnikova and Maria Alyokhina, two members of the Pussy Riot collective, have agreed to sit on the advisory board of an international whistleblower organisation of which Julian Assange is a trustee, after meeting the WikiLeaks founder at the Ecuadorian embassy in London.

The two women, who were imprisoned in Russia for protesting against Vladimir Putin and who are currently touring the UK, told reporters outside the embassy on Tuesday that they found they had “more in common than we expected” with Assange. The Australian has not left the embassy since June 2012 after seeking political asylum in a bid to avoid extradition to Sweden to face accusations of sexual assault.

Assange had asked them to join the advisory board of the Courage Foundation, alongside the philosopher Slavoj Žižek, the Pentagon Papers whistleblower Daniel Ellsberg and others, and they had accepted, the two women said. The organisation, of which Assange is one of three trustees, raises funds for the legal defence of whistleblowers around the world, including Edward Snowden.

Asked if there was any contradiction in members of a feminist collective pledging their support for a man who is wanted over sexual assault allegations, Tolokonnikova, speaking through a translator, said: “We did not review this charge that has been directed at him. We do not think it is in relation to the things that he is doing right now.”

“We also try to … see the direction of one’s intentions in the future, what he is trying to do and is doing right now,” added Alyokhina. Assange’s legal team maintain that he has not been charged with any offence.

The women are in Britain to promote their campaign for prison reform in Russia, and an alternative news agency website called Mediazona, both of which they founded following their release from prison last December after 21 months in jail.

Alyokhina said they and Assange had a “huge amount of things in common”, particularly in relation to the Chelsea Manning case, which they considered “one of the most important cases in today’s world”.

The handful of news organisations invited to cover their visit to the embassy did not include RT, the Russian Kremlin-backed broadcaster which hosted Assange’s chatshow The World Tomorrow, which normally follows the Australian’s movements closely. Tolokonnikova and Alyokhina have been outspoken in their criticism of the channel during their visit, dismissing it as a source of pro-Putin propaganda and saying: “Some people on the left regard it as an alternative source of media … but leftists in the west should realise it’s in no way a leftist channel.”

They had raised the question of RT with Assange, said Alyokhina, “and obviously we disagree with Julian Assange on the RT issue, but it is enough that we definitely agree with each other on the most basic and important things.”