Boris Johnson has said the UK will “contribute” to any new NATO deployments if Russia invades Ukraine.

The prime minister also told MPs that Western allies will react “in unison” to any Russian attack on Ukraine by imposing sanctions “heavier than anything we have done before”.

He condemned Moscow for sending more than 100,000 troops to its border with Ukraine and promised the UK and its allies could not “bargain away” the vision of a free Europe.

Mr Johnson said: “If Russia invades Ukraine, we would look to contribute to any new NATO deployments to protect our allies in Europe.”

He mentioned how the UK is leading NATO troops in Estonia and yesterday supplied anti-armour missiles and further training support to Ukrainian troops.

The PM acknowledged the Met Police’s announcement earlier that they are investigating events in Downing Street and Whitehall that allegedly broke lockdown rules.

But he said he wanted to reassure the country “that I and the whole government are focused 100% on dealing with the people’s priorities, including the UK’s leading role in protecting freedom around the world”.