No 10 says that Prime Minister Sunak won't be going to the climate conference.
The prime minister's office denied this was a lack of commitment.
Liz was due to attend the conference.
The new PM won't be going due to other pressing domestic commitments, according to No 10.
The prime minister's office remains committed to net zero and to leading international and domestic action to tackle climate change The UK is leading the world on net zero.
We will continue to work with Egypt as the host of COP 27 and to make sure that all countries are making progress on the historic commitments they made at the Glasgow climate pact.
She said the UK would be represented by other ministers.
The 27th Congress of the United Nations will be held in Sharm el-Sheikh from 6 to 18 November, the day after Chancellor Jeremy Hunt sets out the UK's tax and spending plans.
The UN climate summits are intended to help governments agree on ways to limit global temperature rises. The UK hosted the 26th Conference of the Parties.
There is no credible pathway to keep the rise in global temperatures below a key threshold of 1.5C, according to a UN report.
People all over the world would be at risk if the temperature goes past 1.5C.
Governments' carbon-cutting plans since last year's climate summit had been woefully inadequate, according to the UN's emissions gap study.
Reducing emissions, helping countries prepare for and deal with climate change, and securing technical support for developing countries will be the focus of the summit in Egypt.
The UN Secretary General told the British Broadcasting Corporation that he would like to see both the Prime Minister and the King in attendance. It appears that neither will be there.
It's odd that the UK government won't have a major political figure in attendance since it was the main driving force behind its limited successes.
The outgoingCOP president is not the same as a prime minister or monarch.
If the leaders of one of the world's leading lights in taking action on climate can't attend the conference, it will not bode well for the event.
A review of the UK's goal to achieve net zero carbon emissions was announced last month.
A focus of the review was to ensure the UK's fight against climate change maximized economic growth, while increasing energy security and affordability for consumers and businesses.
Prime Minister Boris Johnson and Mr Sunak were both present at the previous COP summit.
The governments have been invited to the conference. The Russian President is not expected to attend.
China has not yet said if its leaders will participate in the trip.
Buckingham Palace said King Charles wouldn't be going to the conference.
The monarch has a long-standing interest in environmental issues, but the Palace said it had sought advice from the PM and that "with mutual friendship and respect there was agreement that the King would not attend."