Boris Johnson has hit back at EU plans for further vaccine export controls as he said companies may reconsider investing in nations that impose trade blockades.
The prime minister told the cross-party Liaison Committee he does not think blockades of "either vaccines or of medicines or ingredients for vaccines are sensible".
And in a further warning, he added: "I would just gently say to anybody considering a blockade, or interruption of supply chains, that companies may look at such actions and draw conclusions about whether or not it is sensible to make future investments in countries where arbitrary blockades are imposed."
Mr Johnson was answering a question from former health secretary Jeremy Hunt about vaccine nationalism, hours after the European Commission said it was introducing an export authorisation mechanism based on "proportionality".
President of the European Commission Ursula von der Leyen said "open roads should run in both directions", adding: "The EU has an excellent portfolio of different vaccines and we have secured more than enough doses for the entire population.
"But we have to ensure timely and sufficient vaccine deliveries to EU citizens. Every day counts."
The proposals recommend more transparency and reciprocity but do not go as far as including a ban on exports to the UK.