A critical meeting on climate change, organised by the UK, appears to be the latest victim of an ongoing row with China.
The online meeting of ministers from around 35 countries takes place on Wednesday, but while the US, EU, India and others are taking part, China is not.
London says that China was invited to the event but has decided not to participate.
Relations between the UK and China have deteriorated in recent weeks after angry exchanges about human rights.
Beijing recently imposed sanctions on nine British citizens, including five MPs, for spreading what it called “lies and disinformation” about China in retaliation for measures taken by the UK government and others over human rights abuses against the Uighur Muslim minority group.
A list of invitees was published two weeks ago including China. But when the final list of participants was circulated, there was no China.
With major emitters such as the US, EU and India taking part, it would be expected that China would play a leading role in this type of event.
Not only is it the world’s biggest carbon emitter but it also likes to portray itself as a key ally for developing countries.
Today’s climate and development summit is being described by the UK as a “key moment” in the run up to the UN Climate Change Conference of the Parties (COP26) in Glasgow, Scotland, in November.
Analysts say the UK, as COP26 hosts, has a very tricky diplomatic path to steer with Beijing.
Today’s meeting is seen as an important platform for the countries that are most vulnerable to rising temperatures.
Ministers from several threatened island states and poor countries will take part in the meeting, and they will likely make the point that while they contribute little to the causes of climate change they are already feeling the effects.
Britain will highlight how the poorest who have done the least to cause climate change are suffering the worst of its impacts, and urge rich countries to offer more support.
The virtual meeting will bring together governments, development banks and others to work on solutions to the floods, droughts and extreme heat faced by many developing countries, as well as ways to boost energy access, clean air and smart cities.
A report published recently by African finance ministers indicated that some countries are now spending up to 10% of their GDP adapting to the impacts of rising temperatures.
In November, COP26 will bring together heads of state, climate experts and campaigners to agree coordinated action to tackle climate change.
A COP26 spokesman said China has been invited, adding: “We look forward to working with them on climate change issues.”