In a speech at the conference of the powerful centre-right European Peoples party (EPP), Barnier did not go into details of the deadlocked Brexit negotiations, but warned the EU project was under threat.
We will have to fight against those who want to demolish Europe with their fear, their populist deceit, he told more than 700 EPP delegates in Helsinki, before naming the former Ukip leader Nigel Farage.
Read more In a wide-ranging speech that moved from European defence to electric vehicles, he mentioned Brexit only to promise to fulfill my Brexit mission to the end and make a brief opening joke that his speech would be short because the clock is ticking.
Barnier was speaking as Brexit talks were in stalemate over the issue of the Irish backstop – an insurance plan to avoid creating a hard border on the island of Ireland. A crucial cabinet meeting to agree the UKs Brexit negotiating position was delayed from Thursday to the weekend or early next week amid a row over whether senior ministers should be given the governments full legal advice on the backstop.
Barnier, a former French foreign minister with a long career in centre-right politics, also issued veiled criticism of the French president, Emmanuel Macron, who is seeking to present himself as a defender of Europes liberal and multilateral values, against populists on the far right and far left.
We must also respond to those who think that defending Europe belongs to one single party, Barnier said, without mentioning Macron by name. More than ever before, Europe needs the EPPs founding vision. We are patriots and Europeans.
Touching on the threat of climate change and the need to rid our cities of smog and particles, Barnier revealed that his first granddaughter would be born in a few weeks. In 2050 when our kids are 32, what will our environment look like, if we continue to use the resources of three planets per year? he said.
He also called for European action to invest in new space technology and artificial intelligence, while revealing anxiety about Europe losing out to China or big tech companies. The four GAFAs are bigger than Germany[s economy], he said, using the French-inspired acronym to refer to Google, Apple, Facebook, Amazon.
Delegates also heard from EU leaders Jean-Claude Juncker and Donald Tusk, but neither mentioned Brexit in their short speeches.
Senior EU politicians see little political capital in Brexit and one senior European source told the Guardian they would now cancel a trip to the UK if their agenda was too full. I would prefer to go to Prague or Warsaw than London, because I cannot build anything with the UK.
Meanwhile The Irish Taoiseach, Leo Varadkar, reiterated his determination not to see a hard border on the island of Ireland. We want the future relationship between the EU and UK to be as close as possible, he said. But it must provide a level playing field and the integrity of our single market must be upheld.
He added: The ball is very much in Londons court. Internal British politics is really a matter for them. I just hope Prime Minister May is in a position to get any potential agreement through her cabinet and through her parliament.
The EUs concerns about ensuring European firms are not undercut by British rivals operating under laxer rules on environment, workers rights, state aid, and health and safety, are not new. But they have come to the fore, as both sides seek to break the deadlock on the Irish backstop, which is hindering a November deal.
Negotiators are looking at a UK-wide customs union for the backstop, a concession by Brussels, which had proposed a Northern Ireland only model.
Barnier was speaking shortly before EPP delegates elected to become the next European commission president when Jean-Claude Juncker stands down in 2019. Party favourite, Manfred Weber, a German MEP since 2004, who leads the EPP in the European parliament, triumphed over his rival Alexander Stubb, a former prime minister of Finland.
The two candidates come from different wings of the large group, that is struggling to deal with its most troublesome member, Hungarys authoritarian leader Viktor Orbán.
Brexit, however, is one issue the candidates agree on: both regret the UK decision. Brexit is one of the biggest travesties we have seen in international history, said Stubb, who has a British wife and children with joint nationality. Leaving the European Union is a bit like leaving the internet. You can do it, but its kind of stupid.
Weber said the EU had to show European voters at the 2019 elections there was a benefit to membership. If you dont show the difference between being member of the European Union and being outside that will have a huge impact on the election campaign and that is why we have to be clear, he said. It must make a difference when you are leaving the European Union.
Michel Barnier was humiliated today as EU politicians rudely ignored his Brexit speech to a conference in Finland.
Members of the centre-right EPP group chatted among themselves as the Frenchman tried to deliver a stark message about the threats to the blocs future.
At one point German MEP Manfred Weber stood up and posed for photographs right in front of Mr Barnier – while Angela Merkel walked out half way through.
The behaviour was so bad that Bulgarian PM Boyko Borisov later berated delegates from the stage, complaining that Mr Barnier was updating them on a Brexit process that could provoke a huge cataclysm but they were not interested to hear him.
The extraordinary situation developed at the EPPs gathering in Helsinki, attended by a slew of national leaders as well as commission president Jean-Claude Juncker and Mr Barnier.