Countries backing a strong deal in Glasgow to cut emissions in line with limiting global warming to 1.5C say momentum is growing for their cause.

The “High Ambition Coalition” is calling for countries to submit more ambitious national action plans in the next year that will help keep temperature rises to 1.5C – beyond which the most dangerous climate impacts will be felt.

The coalition said former US president Barack Obama had given his support for their push for an outcome that limits warming to 1.5C at a private meeting at Cop26 on Monday.

And 13 new countries have signed up to the High Ambition Coalition statement calling for ambitious action at Glasgow, ranging from Canada, Italy and Ireland to Uruguay, the Seychelles and Angola.

The coalition said it now has 41 supporters, including the chairs of three country groupings that represent dozens of the poorest countries and those at-risk from climate impacts such as small island states.

US President Joe Biden, Germany’s Chancellor Angela Merkel and French President Emmanuel Macron have also signed up to the statement.

Along with country plans in line with 1.5C, the statement focuses on action on coal, fossil fuel subsidies, methane, and transport, and calls for the delivery of the long-promised 100 billion dollars a year for poorer countries to deal with climate change and more money for helping them adapt to its impacts.

The growing momentum comes as fault lines in the Cop26 climate negotiations become clearer with the arrival of ministers from countries around the world to take over the reins to hammer out a deal in Glasgow.

As countries met for a presidency update on the first week of the UN conference and progress of the negotiations, it was clear that increased action this decade to limit dangerous warming and finance for poor countries were key.

The latest national plans by countries for action this decade still overall leave the world far off track to meet the internationally agreed goal of trying to limit global warming to 1.5C.

So negotiators will try to thrash out a “cover decision” from Glasgow, setting out how countries will close the gap between the plans to cut emissions in this decade and what is needed to avoid temperature rises of more than 1.5C.

While some countries such as those that are part of the High Ambition Coalition want to see new action plans that are in line with 1.5C within the next year, others are pushing back on the bid for accelerating action from the existing five-yearly cycle for revisiting the plans.

There have also been concerns over finance to help poorer nations tackle climate change, with developed countries failing to deliver on a long-promised 100 billion US dollars a year by 2020 until at least next year.

Ministers are also under pressure to finalise the so-called Paris rulebook and make the global Paris climate accord operational and effective.

Over the weekend, the UK Cop26 presidency published a summary of what could be in the final statement from Glasgow – although a draft version of the text is not expected until Wednesday.

It flags the need for urgent action up to 2030 and efforts to scale up finance, among other elements.

Cop26 President Alok Sharma struck a seemingly optimistic note at a press conference on Monday, citing progress made on a framework to address loss and damage from climate impacts in vulnerable countries.

Mr Sharma said: “Those of you who have followed this process will know that loss and damage has historically been seen as a polarising issue, but I am encouraged that the mood music has changed somewhat and there is now a practical recognition that action is needed on this topic in the face of growing impacts.”

He cited the extreme weather seen in developed nations, such as the wildfires in North America and Australia and the flooding in China and central Europe, as one of the catalysts of this shift in mindset.

Mr Sharma said there had been tangible progress on setting up the Santiago Network – a UN body that will connect providers of technical expertise and resources with developing countries to help set up infrastructure to try and avert or at least minimise climate change-induced damage.

“Climate vulnerable communities are particularly at the forefront of my mind and will be so throughout these negotiations,” he said.

“They and the generations to come will not forgive us if we fail to deliver in Glasgow.”

Patricia Espinosa, executive secretary of the UN Framework Conversation on Climate Change, said most ministers have now landed in Scotland, adding: “They are all eager and willing to get involved in the negotiations.”

Ms Espinosa said she was “cautiously optimistic” delegates should “be able to adopt a meaningful group of decisions at the end of this week”.

But elsewhere, campaigners warned the first summary of the final statement was weak, and missing any reference to phasing out fossil fuels, the major source of the greenhouse gas emissions driving global warming.