Climate campaigners say lack of access to coronavirus vaccines has hampered those most affected by climate change from attending the Cop26 conference.

As the global climate summit formally opened in Glasgow on Sunday, campaign groups claimed it was the most exclusionary to date and this would hit the decisions made.

Speaking at a press conference in the blue zone of the summit, Dorothy Guerrero, of Global Justice Now, said the refusal to give more manufacturers, particularly in developing countries, access to produce the vaccine is part of the reason some were unable to attend.

She said: “It is not a crime coming from a developing country or a poor country.

“You’re already saddled by the fact that your country was affected already for many decades, and you are the least responsible for this climate change.

“And yet you could not come here and raise your voice in this important meeting simply because you don’t have access to the vaccine and hence you can’t attend the Cop.”

She said some would-be attendees could not start to process their visa because of a lack of vaccinations from the UK.

Earlier this year, Prime Minister Boris Johnson said the UK, the UNFCCC and partners will work to provide vaccines to party, observer and media representatives registered for Cop26 who are unable to get them otherwise.

Nathan Thanki, of Demand Climate Justice – which was hosting the press conference along with the Cop26 Coalition, said many people from the global south were unable to attend due to problems with visas, quarantine and costs – much of which he believes could have been avoided.

He said this was a “political issue” and a “far cry from the presidency’s stated goal of having the most inclusive Cop ever”.

He added: “When the people are coming from the front lines of the climate crisis… when they are not able to be in room, raise their voices and make their demands, when they have to jump through millions of hoops just to be here and then be tokenised of course you get rhetoric without action.”

Earlier this week, US congresswoman donated Alexandria Ocasio-Cortez donated 10,000 US dollars (£7,250) to a fund to help get young climate activists to the summit.

The Cop26 Coalition was among the organisations which launched the fundraising campaign as it said about 100 delegates from frontline and indigenous global south communities were unable to attend, despite being accredited.

They blamed this on a combination of the high cost of accommodation, Covid-19 travel curbs and quarantine rules.

A UK Government Cop26 spokesperson said: “We have been working tirelessly with all our partners, including the Scottish Government and the UN, to ensure that Cop26 is an inclusive, accessible and safe summit.

“We have helped participants from more than 70 countries become fully vaccinated who would not otherwise not have viable domestic access to vaccination and are currently welcoming people from across the world to Glasgow.”