The Russian invasion of Ukraine has already begun, a Cabinet minister said as Boris Johnson led a crisis meeting of ministers and senior officials to consider the response to Vladimir Putin’s actions.

The Government is preparing to slap sanctions on key Russian figures and businesses after President Putin recognised two breakaway regions of eastern Ukraine as independent states.

At the 0630 meeting of the Cobra committee the Prime Minister was briefed on the latest intelligence after Mr Putin ordered his troops to carry out “peacekeeping” duties in the Donetsk and Luhansk regions.

Health Secretary Sajid Javid said: “We are waking up to a very dark day in Europe and it’s clear from what we have already seen and found out today that the Russians, President Putin, has decided to attack the sovereignty of Ukraine and its territorial integrity.”

The Health Secretary told Sky News: “We have seen that he has recognised these breakaway eastern regions in Ukraine and from the reports we can already tell that he has sent in tanks and troops.

“From that you can conclude that the invasion of Ukraine has begun.”

The Cobra meeting follows an emergency session of the UN Security Council where the UK’s ambassador Dame Barbara Woodward said Russia has “brought us to the brink”, warning that the country’s actions “will have severe and far-reaching consequences”.

She said an invasion would unleash “the forces of war, death and destruction” on the people of Ukraine.

“The humanitarian impact will be terrible on civilians fleeing the fighting. We know that women and children will suffer most.”

She said the Security Council must be united in calling on Russia to “de-escalate immediately”, as well as “condemning aggression against a sovereign nation and defending the territorial integrity of Ukraine”.

“Russia has brought us to the brink,” she said. “We urge Russia to step back.”

The Kremlin said Russian forces will “maintain peace” in eastern Ukraine.

Mr Johnson said on Monday the decision from Mr Putin to recognise Donetsk and Luhansk was an “ill omen” and a flagrant breach of international law.

The Cobra meeting will co-ordinate the UK response and agree a “significant package of sanctions to be introduced immediately”, No 10 said.

Following the meeting the Prime Minister will have calls with other world leaders and will update MPs on the sanctions package at around 12.30pm.

On Monday night Mr Johnson outlined his “grave concern at recent developments in the region” in a call with the Ukrainian president and said he would consider further “defensive support”.

“Prime Minister Boris Johnson spoke to Ukrainian President Volodymyr Zelensky this evening to discuss the deteriorating situation in and around Ukraine,” they said.

“Outlining his grave concern at recent developments in the region, the Prime Minister told President Zelensky that he believed an invasion was a real possibility in the coming hours and days.”

Downing Street also said Mr Johnson told President Zelensky that he would “explore sending further defensive support to Ukraine” at the request of the country’s government.

Later, President Zelensky told his nation “we are not afraid of anyone” after Russia recognised the independence of the separatist regions.

Foreign Secretary Liz Truss tweeted about the new sanctions from the UK on Monday evening after saying Mr Putin’s actions could not be allowed to go “unpunished”.

The European Union and United States were also imposing sanctions in response to the crisis.