The former UK prime minister said the move – which has now been scrapped – jeopardised the peace process.
The EU reversed the plan to use a Brexit deal clause to restrict exports of Covid-19 vaccines from crossing the Irish border into the rest of the UK late on Friday, following backlash from London, Dublin and Belfast.
The Nothern Ireland Protocol is designed to allow the free movement of goods from the EU into the territory, preventing the need for a hard border on the island of Ireland.
The EU initially triggered Article 16 of the protocol, which would have temporarily placed export controls on the movement of vaccines, in a bid to protect its own supplies amid its row with AstraZeneca over its supply contract.
Asked if the move was irresponsible, Mr Blair told Sky’s Sophy Ridge on Sunday: “Yes, it was a very foolish thing to do and fortunately they withdrew it very quickly.”
The former PM said: “I was somebody who negotiated the Good Friday Agreement, it’s brought peace to the island of Ireland and it is absolutely vital that we protect it.
“That’s why what the European Commission did was unacceptable but, as you say, fortunately they withdrew it very quickly.”