Jean-Claude Juncker provoked fury today as he urged critics of the EU to visit WWI cemeteries

Jean-Claude Juncker today provoked fury as he said those who do not believe in the European Union should visit Europe's war cemeteries.

In an astonishing attack on Eurosceptics, the European Commission president dismissed those who criticise the EU as forgetting its role in the years since the Second World War.

The former prime minister of Luxembourg who heads the EU's bureaucracy in Brussels said: 'Europe gains whenever again we point out that Europe is a major project for peace.

'Whosoever does not believe in Europe, who doubts Europe, whoever despairs of Europe, should visit the military cemeteries in Europe.'

Former defence secretary Dr Liam Fox said instead of 'lecturing' Mr Juncker needed to examine whether the EU was 'fanning the flames of nationalism and the rise of the political fringe once again'.

The Vote Leave campaign said Mr Juncker's remarks were 'crass and an insult to the sacrifice those cemeteries represent.'

Mr Juncker's incendiary comments came during a speech in The Hague, in which he said he hoped the issue of Brexit 'could as quickly as possible be put in the attic of world history'.

'If we had to deal for years with this topic, everything will go wrong in Europe,' he said.

Mr Juncker boasted about how David Cameron had been forced to grovel to him for help with the 'self-created problem' of the renegotiation despite have unsuccessfully tried to block his appointment two years ago.

Ruling out a second referendum if Britain votes to leave, Mr Juncker said: 'There must be a 'no' to further renegotiations with the British, who I otherwise really like; not only because the British Prime Minister voted against me to be president of the Commission, but also because he was so happy that we have helped him to get to grips with his problem, his self-created problem.'

Mr Juncker said he had been attempting to limit his comments on the referendum as he admitted he and the Commission were unpopular in Britain.

'I wanted to say a word about the so-called 'Brexit' - without saying anything, because I have thought about saying something about it again and again, but I never did because it is not useful if the president of the Commission becomes involved in the British referendum campaign,' he said.

'The European Commission is even more unloved in the UK than in other countries, and this is already a remarkable achievement, that we manage to be at all unpopular in Britain and every word of the President of the Commission or the Commission in the direction of Great Britain has contrary effects.'

In an attempt to explain his criticism of Eurosceptics, Mr Juncker said when talking about Europe it would be a 'mistake' not to talk about the underlying causes that led to the formation of the EU in the wake of the Second World War.

'Peace is never a sure thing. Anyone who thinks peace would set in eternity, is wrong fundamentally. And there is in Europe again war,' he said.

'If one had talked two years ago about the war in Europe, people have smiled. After what happened in Ukraine and the Crimea, no one smiles.

'And we must never smile because 20 years ago there was war in Bosnia, Kosovo and throughout the Balkans - the Balkans, which remains a highly complex and highly sensitive European region.'

Ukip leader Nigel Farage said: 'If you visit these military cemeteries you realise what can happen when nation states are not democratic.

David Cameron and French president Francois Hollande visited a World War One cemetery yesterday as part of a Franco-British summit

'If you enforce an artificial identity and uniformity you risk a situation like pressure cooker Yugoslavia, which exploded in violence.'

Dr Liam Fox said: 'The military cemeteries of Europe are testament to the failure of the continent to control extremism in the twentieth century. If Britain had not been a free and independent nation, we would have been unable to intervene to protect Europe from the result of its own folly.

'Before we are lectured by the European Commission, we should take a look at the rise of extremism across the continent and ask whether they are helping or hurting. Those in charge of the EU today need to ask if they are fanning the flames of nationalism and the rise of the political fringe once again.

Robert Oxley, a spokesman for Vote Leave, said: 'It is NATO and British diplomacy that have kept the peace on the continent, not un-elected officials like Juncker. His comments are crass and an insult to the sacrifice those cemeteries represent.'

Mr Juncker, 61, became president of the European Commission in 2014, despite opposition from Mr Cameron who tried to block his appointment. His role is to lead the EU's executive arm.