Image copyright Getty Images Image caption Thousands of negotiators and campaigners gather at the annual Conference of the Parties

The UK looks set to be the host of a critical climate conference next year, after agreeing a partnership with its main rival Italy.

It's regarded as the most important gathering on climate change since the Paris agreement was signed in 2015.

Under the partnership deal, the UK will host the main event with a preliminary meeting held in Italy.

While Turkey is still in the running, the UK is now seen as the clear favourite.

A final decision is likely in the next few days as global climate negotiators meet in Bonn.

Italian sceptics

Under UN rules, next year's Conference of the Parties, or COP26 as it's known, will be held in a European country.

The UK has been lobbying hard to secure agreement from other states but has faced strong opposition from Italy.

However, many European countries have been wary of supporting Italy, as the junior partner in their coalition government, the Lega Nord, has been strongly sceptical of climate science.

Image copyright Getty Images Image caption Climate campaigner Greta Thunberg appeared at last year's conference in Poland

There were also questions in some minds about Italy's capacity to host an event which will attract tens of thousands of negotiators, businesses, campaigners and journalists.

Now the two nations have decided to row in together to support the UK as the host of the main meeting, with the Italians hosting preparatory events.

"Today through great joint diplomacy we have agreed a bid for a UK COP26 Presidency in partnership with our friends in Italy," said Foreign Secretary Jeremy Hunt.

"Together, through our continued commitment to work across Europe and internationally, we will build a better world for our children."

The decision now lies with one of the Western European and Others group, one of a number of regional groups within the UN system.

They will now consider the bids of the UK and Turkey, and a decision is thought likely within a few days, as UN climate negotiators from all over the world are currently gathered in Bonn.

"It's now looking likely that the UK will be the hosts after coming to an agreement with Italy who were also in the running," said Christian Aid's international climate lead, Mohamed Adow.

"With Brexit hanging over the process it was not clear whether the UK would win the backing of other EU countries but it is likely that they will."

Previous decisions on the hosting of these major events have often proven contentious. Last year Brazil had agreed that they would host the 2019 meeting, but the newly elected President, Jair Bolsonaro was hostile to the idea so the country pulled out. The conference will now be held in Chile in December.

2020's conference is seen as a major crossroads in the battle against global climate change. It will likely be held just after the next US presidential election.

Image copyright Getty Images Image caption The meeting in 2020 will be the most important since the Paris climate agreement was signed in 2015

President Trump has begun the process of taking the US out of the Paris agreement, but that step does not become final until the conference next year. Most leading Democrats have already said they will keep the US in the deal if elected to the White House.

2020 will also be the year in which governments are due to review their promises to cut carbon in line with the latest science. It will also be the deadline for mobilising the $100bn of support for developing countries to cope with the impacts of rising temperatures.

The UK government believes that it has the diplomatic skills and the credibility to reach agreement among both rich and poor countries at next year's meeting. Officials point to the recent announcement that the UK will legislate for a net zero emissions target by 2050 as proof of the nation's world leading position on climate change.

But some campaigners say that the UK could be doing much more.

"We can be proud of some real progress made and we are making headline commitments to be world leaders, but can we really show a country truly taking the lead in tackling the climate emergency?" said Rosie Rogers, climate campaign lead at Greenpeace UK.

"For example, the government is still allowing oil rigs to drill new wells in British waters and new airport runways to be built. If the UK government won't take the hard decisions on a real zero carbon economy, any claim to leadership will ring hollow."

Follow Matt on Twitter @mattmcgrathbbc.