According to Downing Street, this is due to other “pressing domestic commitments”, primarily the current preparations under way for the autumn budget.
However, critics have said the move is bad for optics, considering that COP27 will focus on implementing some of the measures drawn up at the Glasgow COP last year, and would have been an opportunity for the UK to set an example.
Head of politics at Green Alliance Chris Venables described Sunak’s decision to miss COP27 as a “massive strategic error'' within the context of current global instability.
Rebecca Newsom, head of politics at Greenpeace UK, said Sunak’s decision was akin to a “runner failing to turn up with the baton at a crucial stage of the relay".
“Coming just after the ousting of Alok Sharma from the cabinet, this suggests that the new prime minister neither takes the climate crisis seriously enough, nor recognises the opportunities for Britain to take a leadership role in helping to solve it,” she added.
Newsom also raised the point that following new reports, the UN secretary general said that countries must “re-prioritise climate change or the world faces catastrophe”.
READ MORE: ‘Gentle warnings’: How UK climate policy is spooking the COP27 hosts
Sunak's predecessor Liz Truss said she would attend the conference, after sparking outrage when news came out that she had advised King Charles not to attend.
New environment secretary Thérèse Coffey who has confirmed she will attend COP27, defended Sunak’s decision, and said it would be up to King Charles if he went or not.
This comes after Liz Truss reportedly told King Charles not to attend the conference.
Coffey described the COP as “just a gathering of people in Egypt” to LBC, and said it is not one of the “big political summits”.
She also told Sky News: “I am not aware of, say, President Biden or President Macron, or any of those other people will be there (in Egypt). It is quite standard practice that every five years is the big political gathering.”
However, it has been mooted that Biden will go to COP, with the Egyptian government saying that around 90 world leaders have already confirmed their attendance.
Labour’s Shadow climate change and net zero secretary Ed Miliband said: "This is a massive failure of climate leadership. We were the COP26 hosts and now the UK prime minister isn't even bothering to turn up to COP27.
“What Rishi Sunak obviously fails to understand is that tackling the climate crisis isn't just about our reputation and standing abroad, but the opportunities for lower bills, jobs, and energy security it can deliver at home.”
Former Green party leader Caroline Lucas said: "The signal this gives out to the rest of the world is deeply deeply serious and I would urge Rishi Sunak to think about this again."
On the impact of the no-show on the market, tax associate at Katten UK Christy Wilson said the decision not to attend in order to prioritise the autumn budget seems “credible”.
She said: “Considering the market upheaval in the UK it is therefore vital that the PM and Chancellor get this autumn statement spot on.
“Given that Rishi Sunak introduced the energy price levy when he was chancellor – and is maintaining it now as PM – this is definitely a step in the right direction in terms of showing his commitment to creating a more climate positive economy. In the autumn statement in November, further green taxes may be introduced as, overall, Rishi Sunak seems to be far more committed to net zero than the previous PM.”