NICOLA Sturgeon has urged the Prime Minister to convene an “emergency meeting of the Heads of Government Council” this week.
The First Minister said that the next planned meeting of the leaders of the UK's four governments in September would be too late to discuss the cost of living crisis.
She said there needed to be "a substantial plan" to "avert and mitigate what will otherwise be a crisis of unprecedented proportions."
Her letter to the Conservative leader comes just hours after his spokesman rejected Gordon Brown’s call for an emergency COBRA summit to discuss the impact of sky-rocketing inflation and the looming energy price cap rise.
The spokesman said there was a convention that an outgoing Prime Minister not commit to any significant fiscal interventions.
In her letter, the First Minister said the situation was “fast deteriorating and many people across the UK simply cannot afford to wait until September for further action to be taken.“
She added: “I am therefore writing to seek an emergency meeting of the Heads of Government Council and propose that we, as leaders of our respective governments, meet as soon as possible this week to discuss and agree urgent steps to help those in most need now, and also formulate a plan of action for the autumn and winter ahead.”
Ms Sturgeon said the power of the devolved governments to act was limited as “many of the levers which would make the biggest difference lie” in Whitehall.
She added: “It is also the case that only the UK Government can access and make available resources on the scale required. Therefore, actions by devolved governments alone - though important - will not be enough to meet the unprecedented challenges we face.
“Action is needed now to address significant gaps in help for households, in particular those on low incomes, who are increasingly vulnerable to the impact of rising household costs.
“However, it is also vital, given further increases to energy bills due to be announced later this month, that a substantial plan be developed now to avert and mitigate what will otherwise be a crisis of unprecedented proportions - a crisis in which many people will be unable to feed themselves and their families or heat their homes.
“While few will escape some impact of the cost of living crisis, these impacts are not being experienced evenly.”
Last week, in a provisional forecast, experts at energy consultancy Auxilione predicted the price cap on energy bills could reach £3,687 in October – close to double today’s already record levels.
They also warned it could hit around £4,400 in January.
In her letter, Ms Sturgeon described the tax cuts being promised by Mr Johnson’s likely successor Liz Truss as “irresponsible” saying they would “benefit the relatively better off over those most in need.”
She said the “focus must be on providing targeted support to those most adversely impacted”.
Ms Sturgeon said: “The current crisis requires clear, focused and determined leadership and co-operation to develop and deliver - at pace - a package of interventions to protect those most impacted.
“The Scottish Government recognises our responsibility and is committed to doing all we can. However, we cannot respond on the scale required without action by your Government.
"Such action is needed now and I will make myself and my officials available so that a meeting can take place this week.”
Earlier, the Prime Minister’s official spokesman said Mr Johnson would not be announcing any new measures before he leaves office at the start of September.
They claimed it would be against the convention that an outgoing Prime Minister binds the hands of their successor with a "major fiscal intervention."
He said there would be a conversation with the current Chancellor Nadhim Zahawi to ensure that support measures due to come into effect later in the year remained "on track".
The spokesman said: “Clearly these global pressures mean challenging times for the public. The Government recognised that the end of the year will present wider challenges with things like changes to the price cap.
“That is why, at the start of the summer, we introduced a number of measures to help the public. Clearly, some of the global pressures have increased since that was announced.
“By convention, it is not for this Prime Minister to make major fiscal interventions during this period. It will be for a future prime minister.”
The spokesman denied that Mr Johnson has been “missing in action” despite promising to serve as a caretaker until his successor was appointed.